Basic Troubleshooting

With the key switch on, check to see if the brake light is working.

Verify 12v Accessory Power

The e-bike will not operate unless it has power from the 12v accessory battery. The fastest way to check for that 12vdc power is to operate the brakes. Operating either brake lever should illuminate the brake light, confirming the accessory battery has power.

  • Is the brake light working?
Yes - (Normal) Click Here
No - (Abnormal) Click Here

Basic Troubleshooting

Verify the 12v accessory battery is charged

Connect a 120v extension cable to the Charge Port for 5 minutes. Operate the brakes again.

  • Is the brake light working?
No - (Abnormal) Click Here
Yes - (Normal) See probable issue below...

 


Issue: The 12v accessory battery is dead.

Solution: Leave the 120v cable connected to the Charge Port to fully recharge the internal 12v battery (3-4 hours).

Probable Cause: The 12v accessory battery can quickly drain over 48-72 hours if the Keyed Power Switch is left in the 'on' position (clockwise). When the bike is not in use, keep this key to the 'off' position (counter-clockwise).

Note: If the Keyed Power Switch is 'off', the 12v accessory battery will slowly drain over a 12-14 day period. This is normal. Please refer to the Battery Charging section of this manual.


Troubleshooting - 12v Accessory Power System

 

Service Decision:  Service Shop or Do-it-Yourself?

Okay, its looking like there is an issue with your e-bike that will require some disassembly and internal troubleshooting. If you prefer your local service shop to work on your fat woody, it's time to transport it there . If you're comfortable working on your fat woody yourself and have the proper tools, please continue.

Tools Required:

  • Ratchet w/ Metric Sockets
  • Metric Allen Wrench Set
  • Digital VOM / Multimeter

 

You may want to consider a Fat Woody bike carrier rack. In addition to helping out in this type situation, it's great to transport your Fat Woody to remote areas you might like to explore. Click here for more information.


Safety Note: Elevate rear wheel when troubleshooting the drive system.

Elevate Rear Wheel

When troubleshooting your electric bike, the first thing you always want to do is elevate the rear wheel so the bike doesn't unexpectedly jolt forward.

  • Slide a piece of wood under the cruiser just behind the kickstand. 
  • Lift the rear of the bike by the saddle horn and gently set it on the wood.
  • Ensure the bike is stable. Make adjustments as necessary.

 


Disassembly Required

Top console reconnected and placed in normal position.

Remove the Left Tank Clam

If you haven't done this procedure before, please visit the 'Disassembly' section of this manual and then return to this point.

Re-Connect Top Console

In order troubleshoot the electric drive system, you'll need to temporarily re-connect the top console so components like the LCD Display and Main Power Switch are operable (with the left clam removed).

 

⚠️  Warning: Rather than allow the top console to just balance on top, I recommend placing the top console back in its normal position and reinstalling the handlebars. That way things won't fall or get damaged.

 

Power Up the Electric Drive

Ensure the key switch is turned on (clockwise) and depress the main power switch (far right on top console).

  • Did the LCD Display turn on?
Yes - Sometimes disconnecting and re-connecting a modular connector can fix a bad connection. If you believe this may have fixed your issue, click here.
No - Continue

Check 12v Accessory Battery

The blue 12v Battery Pack is located just below the center tube. On its left side is an on/off switch and a small red LED. When the battery has power and the switch is in the on position ('I' is on), the LED will glow red.

 

  • Is the RED LED lit on the side of the battery pack?
Yes - (Normal) Click Here
No - (Abnormal) Click Here

 


Troubleshooting -  12v Accessory Battery

Toggle Battery Switch

The switch on the side of the battery is also an integral circuit breaker that trips if the battery's 12vdc supply voltage is shorted. Turning the switch off and then on again resets the built-in circuit breaker.

Toggle the switch on the side of the 12v battery pack, ensuring it's in the 'on' position ( 'I' is on ).  

 

  • Did the RED LED turn on?
Yes - It's possible that this may have been the issue. If the switch was in the off position, the cable assembly may have hit the switch. Make sure the cable assembly is held clear of the switch when you zip tie it. If this fixed your problem, click here.
No - (Abnormal) Click Here
*If the LED turns on, but then quickly goes out, it's possible you have a short in the 12v supply circuit. Refer to the 12v Accessory Wiring Diagram. When trying to identify a short, disconnect all the associated connectors. Connect one at a time until you find the circuit that trips the breaker. Once you've identified the circuit, troubleshoot that circuit.

Verify Proper Operation Before Reassembly

Before reassembling the tank clams and top console assembly, its good practice to connect all the top console connectors and do a quick operational check of the electrical systems.

  • Turn the key to enable the Fat Woody electrical systems.
  • Press the main power pushbutton and verify the LCD is operational.
  • Apply slight throttle to ensure rear motor hub turns.
  • Check the lights and horn for proper operation.
  • Check that the rear brake light works.

If everything appears to operate normally, power off, disconnect the console and proceed with reassembly. If you're unfamiliar with the 'reassembly', visit Section 13 - Disassembly & Reassembly and review the Helpful Hints regarding reassembly. 


Troubleshooting - 12v Accessory Battery

Connect 120v to the Charge Port

If the LED on the side of the battery pack still will not illuminate, it's a clear sign the 12v battery is dead. Let's check to see if the 12v battery charger is doing its job. Connect the e-bike charge port to a 120v wall receptacle. Make sure the battery switch is in the 'I' or on position.

  • Does the RED LED turn on when the charge port is connected?
Yes - Let it charge for five minutes and then disconnect the charge port. If the LED goes out, the battery is not holding a charge and may need to be replaced.
No - Possible bad charger. Continue

Remove the Right Tank Clam

Check 12v Battery Charger Plugs

Before we identify the charger as the problem, let's check one other item. The 12v battery pack has two 8" cables coming out of it. One is the 12vdc supply voltage cable (white 2-pin modular connector) that goes to the relay pack.

The second cable is the 12v battery charger cable with a small black plug. That's what you're looking for. It's located along the right side of the center tube, just below the seat post. Check to make sure this plug is connected to the matching charger plug. Plug and unplug the connector to ensure good contact. Note: I tape them so they don't disconnect.

⚠️ Important: Plug the charge port back into the 120v receptacle, or the charger won't be on.

  • Does the RED LED lit on the side of the battery pack now?
Yes - It's possible the 12v battery charger cable had a bad connection. See if the battery will charge now. If you think that might have been the problem, click here. If the battery won't hold a charge, it will need to be replaced.
No - (Abnormal) Continue

Issue:  Possible 12v Battery -or- 12v Battery Charger Problem

At this point, it could be either the battery or the charger. To test the charger for proper operation, use a digital multimeter to measure the voltage from the charger. You should measure approximately 12vdc on the connector from the charger.

If there is 12v on the charger's connector, but the red led on the battery pack doesn't light with the switch in either position, then the battery pack is bad and must be replaced. Order a new replacement 12v battery pack w/charger here.

Note: If the charger looks good, there may be no reason to disassemble the lower unit clam. Replace only the battery and see if that solves the problem. Since the battery and charger come as a set, keep the new 12 battery charger as a spare.

If there is not 12vdc on the charger's connector, the 12v charger must be replaced.

 

There is the slight possibility that is has become unplugged from the lower-unit 120v plug strip (but very doubtful), but either way the lower-unit left clam must be removed.


12v Battery Charger w/ LED - Plugged into 120v Power Strip

Replacing the 12v Accessory Battery Charger

Remove the lower unit left clam to access the battery charger. If you haven't done this procedure before, please visit the 'Disassembly' section of this manual and then return to this point.

Check to see if the 12v battery charger is plugged in and its LED charge light is 'on'. If the LED is not on and it's plugged in to 120v, then the charger is bad. The battery and associated charger come as a set. Order a new replacement 12v battery pack w/charger here.

 


Basic Troubleshooting

Verify Drive System Power

Pushing the Main Power Button on the top console will power-up the electric drive system, which in turn should turn on the LCD Display.

  • Does the LCD Display turn on?
Yes - (Normal) Click Here
No - (Abnormal) Click Here

Troubleshooting - Electric Drive System

 

Service Decision:  Service Shop or Do-it-Yourself?

Okay, its looking like there is an issue with your e-bike that will require some disassembly and internal troubleshooting. If you prefer your local service shop to work on your fat woody, it's time to transport it there. If you're comfortable working on your fat woody yourself and have the proper tools, please continue.

Tools Required:

  • Ratchet w/ Metric Sockets
  • Metric Allen Wrench Set
  • Digital VOM / Multimeter

 

Lightbulb.jpg

You may want to consider a Fat Woody bike carrier rack. In addition to helping out in this type situation, it's great to transport your Fat Woody to remote areas you might like to explore. Click here for more information.


Safety Note: Elevate rear wheel when troubleshooting the drive system.

Elevate Rear Wheel

When troubleshooting the drive system, the first thing you always want to do is elevate the rear wheel so the bike doesn't unexpectedly jolt forward.

  • Slide a piece of wood under the cruiser just behind the kickstand. 
  • Lift the rear of the bike by the saddle horn and gently set it on the wood.
  • Ensure the bike is stable. Make adjustments as necessary.

Disassembly Required

Top console reconnected and placed in normal position.

Remove the Left Tank Clam

If you haven't done this procedure before, please visit the 'Disassembly' section of this manual and then return to this point.

Re-Connect Top Console

In order troubleshoot the electric drive system, you'll need to temporarily re-connect the top console so components like the LCD Display and Main Power Switch are operable (with the left clam removed).

 

⚠️  Warning: Rather than allow the top console to just balance on top, I recommend placing the top console back in its normal position and reinstalling the handlebars. That way things won't fall or get damaged.

 

Power Up the Electric Drive

Ensure the key switch is turned on (clockwise) and depress the main power switch (far right on top console).

  • Did the LCD Display turn on?
Yes - Sometimes disconnecting and re-connecting a modular connector can fix a problematic connection. If you believe this may have fixed your issue, click here.
No - Continue

Jumper 'P12' Connector

Locate Modular Connector 'P12' - Drive System Power On

Just below the 12v accessory battery pack is the area where all the bike's modular connectors are located (about 20 or so connectors plugged together). Typically, there is one or two zip-ties wrapped around the bundle to keep the bundle from hitting the switch on the side of the 12v battery (would disable bike).

Carefully remove the zip-ties and locate modular connector 'P12' coming from the motor controller (silver aluminum box).

 

Warning: When disconnecting modular connectors, never pull on the wires. Depress the locking tab to unlock the connector and pull apart by the plastic casing.

 

Disconnect 'P12' - Jumper Pins 1 & 3

Refer to the 12v accessory wiring diagram. Unplug or disconnect the 'P12' connector. The female side of this plug is what you're looking for, and it's directly connected to the Motor Controller. Jumper (short) pins 1 & 3 with a small piece of wire.

  • Does the LCD Display turn on?
Yes - (Normal) Click Here
No (Abnormal) Click Here

Troubleshooting - 12v Relay Module

Relay Pack - Carefully cut zip-tie and remove plastic cover.

Locate the 12v relay pack. It is the small black plastic box zip-tied to the side of the motor controller (about the size of a deck of cards with wires coming out of it).

Open the Relay Pack

The cover snaps on/off the box, but a zip-tie ensures the cover stays on the box when subjected to vibration while riding. With a pair of wire cutters, carefully cut the zip-tie securing the plastic cover on the box. The plastic box is mounted to the motor controller with double-stick tape, so it should stay in place. 

  • Cut zip-tie & remove plastic box cover.

With key on, check to see if the red PWR LED is illuminated.

Check Relay Module Power Input

The 12v battery pack directly powers this relay module. There are (5) LED's on the relay module. One is red (PWR) and the other (4) are green. Make sure the key is turned on.

  • Is the red PWR LED is illuminated?
Yes - (Normal) Click Here
No - (Abnormal) Click Here

Troubleshooting - Check Relay Operation

Operate brake lever to trigger relays 3 & 4 - LED's 3 & 4 should light up.

Check the operation of the relay module by operating either brake lever. The module should provide an audible 'click' and trigger relays 3 & 4 (illuminating green LED's 3 & 4).

✔︎ Activate the brake lever and LED's 3 & 4 should light.

✔︎ Release the brake lever and LED's 3 & 4 should go out.

  • Does the brake lever operate LED's 3 & 4 properly?
Yes (Normal) Click Here
No (Abnormal) Click Here

 

⚠️  If the LED's are lit and don't extinguish when the brake lever is released, there is a problem. Click 'No' above.


Troubleshooting - Check Relay Operation

Verify Relay 'Trigger Input' Voltages

Using a digital multimeter VOM, measure the voltage on the IN3 & IN4 trigger input wires.

  • When the brake is applied, +12vdc should be applied at both IN3 and IN4.

If the voltages are present and the relays don't trigger, then the relay module is bad and should be replaced.

 

 

 


Troubleshoot the brake circuit wiring.

If the voltages are not present, there may be an open or short circuit in the 12vdc brake circuit. 

Refer to 12v accessory wiring diagram to troubleshoot.


Before removing the relay module, turn off all the power on the e-bike and make careful notes regarding all the wire colors and connection points. I usually take a photo to back that up. A replacement relay module is available in our parts shop


Troubleshooting - Check Relay Operation

With Main Power Switch 'on', LED's #1 & #2 should operate.

Check 'Main Power' Relays

Operating the Main Power Button should trigger relays 1 & 2 (illuminating green LED's 1 & 2).

  • Does the main power button illuminate LED's 1 & 2?
Yes (Normal) Click Here
No (Abnormal) Click Here

Troubleshooting - Check Relay Operation

Verify Relay Contact Closure

Using a digital multimeter/VOM, check to ensure relay #2 has a contact closure (short) when activated.

If there is a contact closure on relay #2, but that short is not detected on the P12 connector, there is a problem with the wiring circuit or P12 connector.

If there is no contact closure on relay #2, but the associated LED is lit, there is a problem with the relay board. Replacement relay boards are available in our parts shop.


Troubleshooting - Check Relay Operation

LED's 1 & 2 not working

Issue: Possible Bad Relay Module

It looks as though the relay module is defective and may need to be replaced. There is one more test that will confirm the module is the problem.

Verify Relay 'Trigger' Input Voltages

  • When the Main Power Switch is operated, +12vdc should be applied at both IN1 and IN2. (LED's 1 & 2 illuminate)

If the voltages are there, then the relay module is bad and should be replaced.

 

 

 

Before removing the relay module, turn off all the power on the e-bike and make careful notes regarding all the wire colors and connection points. I usually take a photo to back that up. Replacement relay module is available here


Troubleshoot Main Power Switch Circuit

If the voltages are not present, there may be an open circuit in the 12vdc power circuit. Refer to 12v accessory wiring diagram to troubleshoot various circuits.


Troubleshooting - 12v Relay Module

Troubleshoot Power Connection

Check the 12vdc power supplied to the relay board.

If the red LED is not lit, check that the relay board is getting 12vdc power. Again, make sure the key is turned on.

With a digital multimeter, measure the voltage across VCC (+12vdc) and GRD wires (not the pins). You may need a small piece of wire or a paperclip to insert into the small connectors. Be careful as they are small connectors and delicate gauge wires that can easily be damaged.

Use a pair of small needle nose pliers to remove the small connectors. DO NOT pull on the wire.

 

  • Is there +12vdc power across the wires?
Yes - If there is +12vdc supplied to the relay module and the PWR LED (red) doesn't illuminate, the board is defective and should be replaced. Replacement 12v relay modules are available in our parts shop.
No - (Abnormal) Click Here

 


Troubleshooting - Electric Drive System

Elevate Rear Wheel

Safety Note: Elevate rear wheel when troubleshooting the drive system.

When troubleshooting the drive system, the first thing you always want to do is elevate the rear wheel so the bike doesn't unexpectedly jolt forward.

  • Slide a piece of wood under the cruiser just behind the kickstand. 
  • Lift the rear of the bike by the saddle horn and gently set it on the wood.
  • Ensure the bike is stable. Make adjustments as necessary.

Check Throttle Operation

Ensure the rear wheel is elevated and free to spin. Gently apply throttle. 

  • Does the Thumb Throttle operate the rear wheel?
Yes (Normal) - Click Here
No (Abnormal) - Continue Below 

 

⚠️  Note: If the hub motor is trying to operate, but is having some mechanical problems or oscillations, select 'yes' above.


Important Note: The electric drive system is operationally disabled when the brakes are applied. Verify the brake levers are not operated.  If the throttle is still not working, please continue.


Service Decision:  Service Shop or Do-it-Yourself?

Okay, its looking like there is an issue with your e-bike that will require some disassembly and internal troubleshooting. If you prefer your local service shop to work on your fat woody, it's time to transport or ride it there (manually pedal). If you're comfortable working on your fat woody yourself and have the proper tools, please continue.

Tools Required:

  • Ratchet w/ Metric Sockets
  • Metric Allen Wrench Set
  • Digital VOM / Multimeter

 

Lightbulb.jpg

You may want to consider a Fat Woody rear bike carrier rack. In addition to helping out in this type situation, it's great to transport your Fat Woody to areas further away you might like to explore. Click here for more information.


Disassembly Required

Remove the Left Tank Clam

If you haven't done this procedure before, please visit the 'Disassembly' section of this manual and then return to this point.

Re-Connect Top Console

In order troubleshoot the electric drive system, you'll need to temporarily re-connect the top console so components like the LCD Display and Main Power Switch are operable (with the left clam removed).

 

Warning: Rather than allow the top console to just balance on top, I recommend reinstalling the top console back in its normal position. That way it won't fall or get damaged.



Troubleshooting -Electric Drive System

Drive System Major Components

Troubleshooting the electric drive system is a process of elimination. There are four major components to the electric drive system:

  • Battery Pack  (and associated battery charger)
  • Motor Controller
  • Motor
  • LCD Display (Cycle Analyst V3.0 Electric Vehicle Management System)

 

Drive System Operational Overview

Builder's Note: To better understand what may not be working correctly, it's important to have a fundamental understanding of how the electric drive system functions. Take a moment to review this information as it will help you better understand the troubleshooting process we'll take. 
>> Skip directly to Troubleshooting Drive System
⚠️ The cables shown between the various components in these diagrams are representative of cable assemblies, representing multiple wires/conductors between the components. For more detailed wiring information, please refer to the schematic diagrams.

Battery Pack

Click to enlarge: Battery Pack shown disconnected from Motor Controller

The battery is the most essential component of the electric bike system. Without power, nothing happens.

The powerful lithium ion battery pack on your Fat Woody cruiser is rated at +50vdc. When it's fully charged, it puts out around +58vdc. As you ride your bike, that voltage will continue to drop. To protect the battery from too deep a discharge, there is a programmable 'low voltage cut-off' or LVC threshold of around 48v, where the CA computer management system start to shut down power output.

Note: Over the life of the battery (600-700 charge cycles), this voltage (+58v) will continue to slowly drop. This is normal.

 

Motor Controller

Clink to enlarge: Electric gateway closed when no throttle is applied.

The motor controller is the electric gateway component between the battery pack and the motor. Without it, the motor would spin at full speed until the battery ran out of power.

The motor controller is appropriately designed to operate within the voltage range of the battery pack, as well as operate with the limits of its current capability. The Fat Woody motor controller is rated to 60v @ 40 amps.

Once the 50v battery is plugged into the motor controller, the motor controller provides a small amount of that battery power (+5vdc) to operate the Cycle Analyst computer.

 

Electric Motor

Click to enlarge: Applying throttle opens electric gateway to motor hub.

The electric motor is not really an intelligent device, but rather just spins when voltage is applied to it. The more current (amps) fed to it, the faster it will spin. Conversely, the less current you feed to it, the slower it spins.

Throttle

The thumb throttle tells the motor controller how much electric current you want to send to the motor. In the case of the Fat Woody cruiser, the throttle tells the Cycle Analyst computer, and the CA relays the information to the motor controller. This allows the CA computer to impose preset programmable limits relating to power and speed.

 

Cycle Analyst Computer/LCD Display

Click to enlarge: E-bike power output is ultimately controlled by the CA.

If the CA computer is programmed to limit the power output of your e-bike, the throttle output signal it sends to the motor controller will be less and subsequently, the electric motor will spin slower. You can adjust these preset limits in the Cycle Analyst set-up menu.

Additionally, the Cycle Analyst employs a temperature sensor in the electric motor. If the motor hub begins to overheat, the computer will automatically rollback the amount of throttle applied to the motor controller until the temperature comes down.

 

Brake Lever:  Throttle Inhibitor

Click to enlarge: When brakes are applied, all power to motor shuts down.

For safety reasons, your brake levers have been directly connected to the motor controller for the purpose of over-riding any throttle input, essentially inhibiting any power flow to the motor hub.

For this reason we'll disconnect it, as it is the first thing to rule-out when troubleshooting electric drive issues.

 

 

 

 

 

>> Continue to Troubleshooting Drive System


Common Operational Issues

This section of the Technical Service Manual will continue to be a 'working list' of issues that may be encountered, and possible troubleshooting procedures and solutions.

Please select an issue that most closely describes the problem you may be experiencing. If you don't see it on the list, please contact us and we'll help to resolve your issue and add it to this resource.



Troubleshooting - Check 12v Power Connectors

If your 12v accessory battery LED is lit and you have no power to the relay board, you'll need to check the 12v power connectors between the battery and the relay pack. At this point, you may want to refer to the 12v accessory wiring diagram.

Locate Modular Connector 'P1' 

Just below the 12v accessory battery pack is the area where all the bike's modular connectors are located (about 20 or so connectors plugged together). Typically, there is one or two zip-ties wrapped around the bundle to keep the bundle from hitting the switch on the side of the 12v battery (would disable bike).

Carefully remove the zip-ties and locate modular connector 'P1' coming from the 12v accessory battery pack.

 

Helpful Hint: It is not always necessary to disconnect modular connectors to get electrical measurements. Most multimeter lead tips are able to contact connector pins where the wire is inserted into the connector.

 

Warning: When disconnecting modular connectors, never pull on the wires. Depress the locking tab to unlock the connector and pull apart by the plastic casing.


Check Voltage Across 'P1' Connector

Using a digital multimeter, verify 12vdc on the 'P1' connector.

  • Is there 12vdc across the terminals?
Yes (Normal) Continue
No (Abnormal) Bad Connector or Battery

 

 

 

Check Voltage on 'P2' Connector

Using a digital multimeter, verify 12vdc on both pins of the 'P2' connector.

  • Is there 12vdc on both the terminals?
Yes (Normal) Continue
No (Abnormal) Check Key Switch/Wiring

 

 

 

Check for Open Circuit

If you have 12vdc at 'P1' and 'P2', and it is not present at the relay module, then you have an open circuit in the wiring between 'P2' and the relay module.

Refer to the 12v accessory wiring diagram.

Solution: Identify open circuit and restore continuity.

 


Troubleshooting - Electric Drive System

 

Disconnect Brake Activated Throttle Inhibitor

Just below the 12v accessory battery pack is the area where all the bike's modular connectors are located (about 20 or so connectors plugged together). Typically, there is one or two zip-ties wrapped around the bundle to keep the bundle from hitting the switch on the side of the 12v battery (would disable bike).

Carefully remove the zip-ties and locate modular connector 'P11' coming from the motor controller (silver aluminum box).

 

 

Warning: When disconnecting modular connectors, never pull on the wires. Depress the locking tab to unlock the connector and pull apart by the plastic connector housing.

 

Disconnect Modular Connector 'P11'

Disconnect modular connector 'P11' - Brake Activated Throttle Inhibitor

Modular connector 'P11' is a dry contact closure - brake-activated input to the motor controller. It serves to operationally disconnect the throttle and shut down any power flowing to the motor.

Disconnecting this connector ensures that the electric drive system is not operationally disabled by a brake signal, allowing for unencumbered troubleshooting of the electric drive system.

⚠️  Turn the Drive System on.

 

 

  • Does disconnecting 'P11' enable the throttle to operate the motor?
Yes - If the Yel/Grn wires on the male side of the 'P11' connector are shorted, and the brake lever is not activated, there may be a problem with 12v relay module or a short in the wiring of this circuit. It should only short (contact closure) when the brake lever is activated. Click here.
No (Abnormal) Continue

Troubleshooting - Electric Drive System

Check Battery Pack Voltage

Verify battery voltage is between 50-58vdc.

Without power, nothing happens. The first place to start troubleshooting is the battery pack. Using a digital multimeter (VOM), measure the voltage at the battery connector. Fully charged, it should be 57-58vdc, but if it's below 50vdc that could be a problem.

In order to measure the battery voltage, you will need to disconnect the main battery supply connector. Be aware that when connecting or disconnecting the battery connector, the conductors can arc. This is normal, but be careful and don't short the battery conductors.

Locate Main Battery Supply Connector

The main battery supply connector is located in the same connector bundle as the 'P11' connector. It's the biggest cable in the bunch. There is also a smaller battery charger cable that comes out of the battery pack, so don't confuse the two.

  • Is the battery voltage greater than 50vdc?
Yes - (Normal) Click Here
No - (Abnormal)  Continue Below

Check Battery Charger

Check the voltage output from the battery charger.

The battery charger is pretty much the work horse of the e-bike system. It is also one of those items on the short list of 'common failures'. It should have a 58vdc output voltage. Again, you'll have to disconnect its connector to measure its output.

⚠️  Make sure you plug in your e-bike 120v charge port, or you won't see any voltage output.

If it's doing its job, your battery pack should be charged. If your battery charge is low, the battery charger is the most likely culprit. The battery charger itself is located on the right side of the top tube. To gain access to it, you need to remove the right tank clam. It does have a small LED on the side of its case, but that doesn't always provide useful information.


Replacing the Battery Charger

While not shown in the photo, the 2 amp battery charger has a 120v cable that plugs into the side. When replacing the battery charger on your Fat Woody cruiser, discard the 120v cable that comes with the new charger and use the one already installed on your bike.

Note: To replace the 120v cable on the bike, you need to disassemble the lower unit. That's a lot of unnecessary work. If you suspect the cable is bad, check the voltage at the 120 plug (w/charge port plugged in).

Replacement battery chargers are available in our parts shop.

 

Replacing the Battery Pack

If you verify the charger is operating properly and the battery pack does not appear to be charging, it's best to replace the battery pack rather than open it and attempt repair.

In order to replace the battery pack, you will need to disassemble the lower unit. Please visit the 'disassembly' section if you have not done this before.

Replacement battery packs are available in our parts shop.


Troubleshooting - Electric Drive System

Motor Controller Outputs

The battery pack feeds directly into the motor controller where the power is split into two (2) outputs. Obviously the main 50v output is used to feed the drive motor, but there is also 5v output that is used to power the LCD display. If the LCD display is not operating, there's a good chance the problem may lie with the controller's 5v output.

  • Is the LCD Display working?
No - (Abnormal) Click Here
Yes - (Normal) Continue

 

Tools of the Trade

Motor/Controller Tester

Once you've ruled out the battery pack as the problem, and the LCD Display appears to be operating properly, you're really only left with the motor or the controller.

An issue with the motor, controller, or motor-to-controller connection can appear to be mechanical in nature. Testing is always best done with the motor unloaded, spinning freely.

In order to troubleshoot the motor controller and motor, every e-cruiser we sell includes a very handy Motor/Controller Tester intended for troubleshooting your e-bike motor and controller.

If you're a shop technician working on one of our e-cruisers, ask your customer for this tester. They're also available in our parts shop for around $30.


Motor & Controller Overview

In order to troubleshoot the motor/controller, you must first have a fundamental knowledge of how a brushless DC motor operates.

This video that does a great job of visually explaining how a 3-phase brushless motor works. The example motor used is a small computer fan, but essentially it is the same concept as the rear hub on your electric bike.

We're not looking to make you an expert on motors, but rather just familiar with the concept and the relationship between motor windings and hall effect sensors (for proper timing).

 


 

Troubleshooting the Motor-to-Controller Connection

While the video above didn't dive too deep into how the controller actually works, you only need to grasp the concept of its relationship to the motor.

The first test is to see if the controller output voltages and signals are operating correctly.

As stated previously, the cables shown in this simplified diagram have multiple conductors. You can take a closer look at this connection on the schematic wiring diagram.


Important Note: The small Hall Sensor wires are quite delicate and the pins in the plugs can back out. If that happens, the smooth timing sequence on the motor is thrown off and can feel like a mechanical issue.

A poor connection between the motor and controller is the most common cause of intermittent, poor, or non-function issues.


Connect the Tester to the Controller

The right half of the Testor is for checking the motor controller's output.

The motor controller has two cable assemblies that connect it to the motor. One cable assembly is the thicker gauge Phase Wires (Yel/Grn/Blu). The other smaller gauge cable is the Hall Sensor Wires.

In order to perform the test, the motor-to-controller cable assemblies will need to be disconnected.

⚠️  Turn OFF the electric drive system (main power switch).

Connect the Tester to the motor controller output cable assemblies.

 

Test the Controller

The Tester performs two different functions. The right half of the tester is for testing the controller while the left half is for testing the motor. The Tester does have an internal 9v battery, but that is only used when testing the motor. This first test will check to make sure the motor controller is putting out the correct voltage and Hall Sensor timing sequences.

⚠️  Turn ON the main power switch to power up the controller.

✔︎  The smaller LED in the center of the Controller Tester should flash, indicating 5v power is present for the Hall Sensors.

✔︎  Press the throttle half way and the six indicator LED's (circular pattern) should flash two by two in sequential order.

  • Does the motor controller appear to be triggering the LED's properly?
Yes - (Normal) Click Here
No - (Abnormal) Replace Controller

If it doesn't flash two LED's at the same time, rotating in a pattern, then the motor controller is not functioning correctly and should be replaced. A replacement motor controller is available in our parts shop.


Troubleshooting - Electric Drive System

Connect the Tester to the Motor

⚠️  Turn off the main power switch to the electric drive.

It won't be required to test the motor. The Tester's 9v battery will supply the necessary power to check the motor. Ensure the 9v battery is fresh or it could effect proper testing.

Like the controller, the motor has two cable assemblies. One cable assembly is the thicker gauge Phase Wires. The other smaller gauge cable is the Hall Sensor Wires.

In order to perform the test, the motor-to-controller cable assemblies will need to be disconnected.

 

Test the Motor

As indicated previously, the Tester performs two different functions. The right half of the tester is for testing the controller while the left half is for testing the motor. This second test will check to make sure the motor windings and hall sensors are properly functioning.


1.  Test the Motor Windings (Coils)

Locate the three alligator clips on the back of the tester labeled Motor Coil. Connect them to the three Phase Wires on the motor cable assembly.

⚠️  Turn ON the Tester power switch.

Rotate the rear wheel/hub in the opposite direction of normal forward rotation. The three indicating LED's on the top row of the tester should flash in sequence.

✔︎  If any of the LED's fail to flash, either the motor windings have a fault or you have a bad connection.

2.  Test the Motor Hall Sensors

Locate the modular connector on the back of tester labeled Motor Hall Signal Wire. Ensure the red and black power wires are correctly matched before connecting the modular connector to the motor cable assembly. 

⚠️  Turn ON the Tester power switch.

Rotate the rear wheel/hub in the opposite direction of normal forward rotation. The three indicating LED's on the second row of the tester should flash in sequence.

✔︎  If any of the LED's fail to flash, either the motor hall sensors have a fault or you have a bad connection.


  • Does the motor appear to be testing properly?
Yes - (Normal) Click Here
No - (Abnormal) Continue

If either of the motor tests indicate there is a fault within the windings or hall sensors, replace the motor hub. 

If the motor tests indicate the electrical portion of the motor appears to be working properly, but there is still some sort of mechanical issue, its possible the integral clutch or reduction gears may be damaged. These items can be replaced without replacing the entire motor.

Replacement motors and motor parts are available in our parts shop. Replacing the motor hub is a specialized procedure involving wheel disassembly. Please visit the wheel disassembly section for detailed instruction on how to do this properly.


Troubleshooting - Throttle Circuit

The last part of the troubleshooting process is the throttle circuit. On most e-bikes, the throttle connects directly to the motor controller, however on the Fat Woody the throttle connects to the Cycle Analyst (CA) and then the CA connects to the motor controller.

Throttle Operation Overview

The throttle operates with a three (3) wire circuit. Pins 1 & 2 are +5.0vdc (red/black) provided by the CA to feed to the thumb throttle. Pin 3 is the return wire that indicates the position of the thumb throttle (based on voltage).  It's referred to as the throttle input signal wire 'Thi'.

For example, with no throttle applied, the 'Thi' signal wire has 0vdc. At full throttle, the 'Thi' signal wire has +5.0vdc (or somewhere between +4.0-5.0v).

⚠️ Note: The voltage on pin 3 can only be measured with the thumb throttle connected.

 

Troubleshooting - Throttle Signals

There is a little risk when measuring the 5vdc supply voltage to the thumb throttle. If you inadvertently short pins 1 & 2, you run the risk of damaging the CA LCD Display output. The easier way to check the throttle signal is to let the Cycle Analyst measure the voltage for you. You can view real-time throttle Thi signal voltage in the Cycle Analyst Setup Menu.


Enter the Cycle Analyst V3.0 Setup Menu

The CA 'Setup Mode' is accessed by pressing and holding the left button for several seconds, or by holding the right button down while the CA is powered up. It is a 2-level deep menu list organized into 13 high level groups to let you adjust over 60 different settings. Remember pressing the left/right buttons toggle the menus left/right (or up/down), while pressing & holding the right button opens that menu or selects an item for modification.

There are also a few visual cues to help with navigation. Arrows on the left and right show when there are more items in the current menu level, while a straight bar indicates you are at the end of the list, and pressing the next button will take you up a level.

Once you enter the 'Setup Mode', you can toggle through a series of 13 category menus you can select from and/or modify. Each category menu provides a small preview line showing some of the key settings and real-time input signals for that category.

Once in the setup mode, pressing the left/right buttons will toggle through these 13 category menus.

Once in the setup mode, pressing the left/right buttons will toggle through these 13 category menus.


Navigate to Screen #3 - Setup Throttle In (Thi)

The preview line (line 2) shows measured voltage of throttle input, the equivalent % throttle that this voltage corresponds to, and the throttle mode (amps, speed, pass-thru, etc.)

The red data on the preview screen indicates real-time data and voltages. Moving the thumb throttle should increase/decrease the voltage shown in the preview screen. The normal range of voltage should vary from 0-5vdc.

Continue to cycle through the screens and you will exit Setup Mode, and be returned to the User Mode of operation.

For more detailed information on the Setup Menu, please visit the CA Programming section.


Note: Screen #4 - Setup Throttle Out (Tho)

Throttle Out (Tho) is the throttle signal from the CA to the motor controller (again, 0-5vdc). The CA does not display real-time Tho output voltage data.

This area of the setup menu actually only provides the ability to adjust CA output voltages based on thumb throttle input voltages.

The only way to measure the actual voltage output  (Tho) of the CA is across pins 2 & 6 while the connector is connected and operating the throttle. Normal voltage values across these pins will vary from 0-5.0vdc depending on the position of the thumb throttle.


If any of the of the voltages above fall outside normal values or are not present, the Cycle Analyst has an issue and should be replaced. Replacement CA LCD Displays can be found in our parts shop.


Troubleshooting - Electric Drive System

Check Output Voltage to LCD Display

The secondary function of the motor controller is to provide 5vdc power the Cycle Analyst LCD Display.

Using a digital multimeter VOM, measure the voltage on pins 1 & 2 of the CA-DP connector coming from the motor controller. There should be +5vdc across these two pins.

⚠️  Make sure the controller is powered on.

❗️ Do not short these pins during the measuring process!

 

  • Is the Controller providing voltage on pins 1 & 2?
Yes - (Normal) Replace Cycle Analyst LCD Display
No - (Abnormal) Replace Controller

 

If the +5vdc voltage is present and the LCD display is not operating, replace the Cycle Analyst.

If the +5vdc voltage is not present, it appears there is a problem with the motor controller's low voltage output and it should be replaced.

Replacement motor controllers and LCD displays can be found in our parts shop.


Common Operational Issues

Speedometer Overview

The speedometer sensor is mounted to the left front fork and connects directly to the Cycle Analyst LCD Display. It is vertically mounted on the inside of the fork - closest to the rim and held in place by two zip ties.

A small circular magnet is mounted to the side of the rim with heavy duty double-sided adhesive tape (about 1/16" thick).

Every time the magnet passes by the sensor, the CA counts that as one wheel rotation, which allows the CA to calculate your speed.


Speedometer Not Working

If your speedometer is not working, it is most likely one of the following issues.

Check the wheel magnet, pick-up sensor and modular connector.

Check the wheel magnet, pick-up sensor and modular connector.

✔︎  The speedometer sensor is no longer positioned correctly. Ensure it is positioned closest to the rim and the line on the sensor aligned with the center of the speedo magnet.

✔︎  The speedo magnet was knocked off and must be replaced.

✔︎  The modular connector to the CA is disconnected or has a poor connection. This is one of the multiple connectors connecting the top console to the e-cruiser - small white two-pin connector.


Common Operational Issues

What are throttle oscillations?

Throttle oscillations are a pulsing-power type feeling you might experience when accelerating. 


Why do they occur?

When you utilize preset limits to control current, power or speed, the Cycle Analyst implements several feedback loops that compare programmed values to actual measured values (e.g. configured speed limit vs. actual speed). The CA then attempts to correct the difference by adjusting throttle output to the motor controller.

The CA can make changes to throttle output very quickly. Sometimes, faster than the measured feedback. Simply put, the computer applies throttle on, then throttle off, and the process repeats.

These oscillations can be tuned through the Cycle Analyst gain settings. Basically, it dampens the computer's response or throttle output, so that adjustments are applied slower.

Tuning is typically accomplished by increasing the gain (of the associated parameter) until oscillations occur, and then backing it off slightly until they go away. You will need to enter the CA Setup Menu to modify gain settings.


Tuning Challenges

When you utilize multiple preset limits vs. a single preset limit, things can get a bit more complicated. Unfortunately, tuning multiple parameters at once is something of an art form.

The simple approach is to stick with a single preset limit parameter as shown above. In other words, limit power, amps, or speed, but not all three simultaneously.

That's not to say you can't do it, just be prepared to spend some time tuning, as they all inter-relate.


Tuning Multiple Parameters Simultaneously

The biggest challenge when tuning multiple presets is figuring out which of the three limits is causing the oscillation. To help determine which preset limit is causing the issue, the Cycle Analyst has a Diagnostic Screen that is easily viewed in User Mode.

On the lower left side


Common Operational Issues

Throttle Sticking

The thumb throttle should operate smoothly when pushed and return completely to the throttle off position.

⚠️  If it sticks in any way, do not ride the e-cruiser under power until the issue is resolved.

I have seen situations where temperature or other issues have affected complete spring-back to throttle off.

There are three (3) small screws that hold the throttle assembly on the handlebar mounting clamp. Rather than work on the throttle upside down, I find it easier to loosen the allen screw on the mounting clamp and rotate it upwards where I can see what I'm doing.

There is wiper-like arm that rotates on an allen bolt. Loosening this bolt can reduce tension on the wiper arm. 

In another case, I've seen the white conductive material (seen on wires) harden and get on the wiper arm contact area, causing friction in spots. Once cleaned off, all was good. 


Common Operational Issues

Mechanical Issues with Electric Motor

The electric motor on your Fat Woody e-cruiser is a geared hub (vs. a direct drive hub). This means it uses composite reduction gears and a clutch to increase torque. If your motor has some sort of mechanical failure, these components are the most likely place for breakage or failure.

Builder's Note: Your Fat Woody e-cruiser feeds over 2000 watts to the electric motor. Because the fat tires provide incredible traction, the weak link between motor and road is the clutch and gears. Heavy throttle from a standing stop/start places great stress on these components and will eventually break them.

Before you can be certain it's a mechanical issue, it's important to understand the motor has electrical hall effect sensors that control the timing of the brushless electric motor.

⚠️  If there is a problem with electrical hall effect timing, it can feel mechanical in nature.

You'll want to be sure if its electrical or mechanical, so check out the section on Testing the Controller & Motor to rule out an electrical issue. If it's an electrical issue (controller or motor), it's best to just replace the bad component. If it's not an electrical issue, most likely it's mechanical (the gears or the clutch). If that's the case, you have the option of just replacing those mechanical parts and not the entire motor hub (less $).


You have a few options when faced with a motor issue. 

1. Replace the entire Motor Hub

You can just replace the entire motor hub, but that involves completely disassembling the wheel, de-lacing spokes (old motor), re-lacing spokes (new motor) and truing the wheel. You can always remove the wheel assembly yourself, but the wheel rebuild should be done in the shop by a pro. The wheel rebuild is typically about $100 labor (in addition to the new motor cost). Visit the section on Removing the Motor Hub (or have your shop visit it).

Replacement motor hubs are available in our parts shop.

 

Aluminum Hub

2. Install a new Motor Assembly into your existing Hub

Personally, I don't like de-lacing and re-lacing a wheel for a few reasons. One, it costs $100-110. Two, the wheel may not be as true as it currently is. Three, the process can scratch the rim.

⚠️  I'll say that again, "The shop will most likely scratch your rim removing/replacing spokes."

If you leave the original aluminum hub laced into the wheel, you can just replace the internal motor assembly from the new replacement motor. No need to remove/replace spokes.

Simply order a new motor hub, remove the motor assembly and install that new motor assembly into your wheel/hub.

 

3. Replace only the Gears & Clutch

This is a more cost effective solution if you or your shop has the capabilities. The hub can remain laced in the wheel while the motor assembly is removed for service.

The clutch will most likely require a gear puller tool, but from there it's pretty straight forward.

Replacement Clutch and Gear Kits are available in our parts shop.


Routine Maintenance - Brakes

Shimano BR-M375 Caliper

Disc Brake Caliper

Your Fat Woody is equipped with a pair of Shimano BR-M375 Disc Brake Calipers. These calipers will require routine adjustment on a regular basis for optimal performance..

The most frequent routine maintenance adjustment is tightening the brake cable. This is needed when the brake lever pulls all the way to the grip with little braking force. It's very quick and easy, and takes only a minute or two.

The second type adjustment (less frequent) is installing/adjusting the caliper position on the disc rotor and brake pad clearance. If you hear the disc rotor hitting/rubbing the brake pads at a certain point of the wheel's rotation (vs. hearing rubbing for the complete rotation), this adjustment/alignment might be required.

 

⚠️  Caution - Disc brakes have a burn-in period, and the braking force will gradually increase as the burning in period progresses. Make sure that you are aware of any such increases in braking force when using the brakes during the burn-in period. The same thing will happen when the brake pads or rotor are replaced.


Adjusting the Brake Cable

Brake cable needs adjustment when lever comes too far back.

This procedure is pretty straight forward and easy to perform.

If your brake lever is coming too far back before it actually applies the braking force, you need to tighten the brake cable by performing a brake cable adjustment.

This adjustment is typically required because the brake cable pulled/slipped through the cable clamp, probably by pulling a little too hard on the lever. That's normal operation and it is easily re-adjusted.

The procedure is the same for both front and rear brakes.

Tool Required: 10mm Wrench

⚠️  Important Note: Adjusting the brake cable works well when the caliper is properly positioned with respect to the disc rotor. If the caliper is not properly positioned, the caliper will need to be adjusted before adjusting the brake cable tension. Follow the caliper adjustments section further below.

Check the brake lever to ensure that there are no problems with any components, and also that the rotors and the pads do not interfere with each other when the wheel is rotated.

The brake should engage about a third to half way back.

 

 

If you prefer, you can use a couple spacers between the brake pads and the disc rotor. The most innovative tool to use as a spacer is an old plastic credit card or a thicker business card.

Cut it into a couple smaller pieces and insert a piece on each side of the disc rotor. Rotate the adjustment arm to clamp the spacers and then tighten the cable clamping bolt.

Remove the plastic spacers and you're properly adjusted.

Lastly, small precise brake cable adjustments can be made both on the caliper and the brake lever cable adjusting bolts - thumb and forefinger tightening. No tools required for that adjustment, but it is limited.


Installing/Adjusting the Brake Calipers

Adjusting the brake caliper is done whenever the caliper is installed for the first time, or if the caliper fixing bolts are loosened.  

Caliper Adjustment Washer Kit

Your Fat Woody e-cruiser has been provided with a high quality titanium caliper adjustment kit. This kit allows the caliper to be precisely adjusted for optimal alignment with the rotor disc.

1. Install the caliper to the aluminum caliper adapter using the adjustment washers and caliper fixing bolts provided. You will be using a thread-lock adhesive, but we'll apply that after the adjustment is properly set. In the event you need to pull it back apart, the adhesive won't get on your components.

2. Install the wheel. The caliper can only be installed after the bicycle wheel / brake rotor is mounted.

3. Loosen the caliper fixing bolts. This allows the caliper to move laterally (left/right) on the adapter bracket while fitting it over the disc rotor and attaching it to the frame.

4. Install the caliper clamp bolts (with lock washers) and tighten. The titanium caliper fixing bolts should still be loose and the caliper will move about a little bit.

 

4. Install the caliper clamp bolts (with lock washers). The titanium caliper fixing bolts should still be loose and the caliper will move about a little bit. Apply pressure to the adapter in the counterclockwise direction while tightening the caliper clamp bolts.


Securing the Brake Cable

1. Pass the brake cable through the cable adjusting bolt, and then under the loosened cable clamp. Leave the brake arm in the idle position and gently tighten the cable clamping bolt. You don't need to torque it at this point.

The brake caliper fixing bolts should still be loose at this point, and the caliper should be free to move about slightly.

On the inboard side of the brake caliper is a pad adjusting screw that moves the inboard brake pad in/out.

2. Using a 5mm allen key, loosen the pad adjusting screw all the way out (counterclockwise) till it stops and then tighten 4-5 clicks (clockwise).

 

3. Loosen the cable clamping bolt and rotate the brake adjustment arm until tight. Pull any slack out of the brake cable and tighten the cable clamping bolt.

4. While depressing the brake lever, set the calipers to the required position and then tighten the two caliper fixing bolts alternately by small amounts each time.

 

5. Loosen the cable clamping bolt to release the tension on the brake caliper.

 

6. Loosen the pad adjusting screw by two or three clicks.

The inboard pad is stationary and does not move when the brake caliper is operated. Only the outboard pad moves.

⚠️ The goal here is to adjust the inboard pad out just far enough that it does not touch the disc rotor while the wheel turns freely.

 

7. Adjust the brake cable tension by loosening the cable clamping bolt and rotating the brake adjustment arm until tight. Before tightening the cable clamping bolt, back off the adjustment arm just enough that the outboard brake pad doesn't rub the disc rotor while the wheel spins freely. 

8. Check the brake lever to ensure that there are no problems with any components, and also that the rotors and the pads do not interfere with each other when the wheel is rotated.

The brake should engage about a third to half way back.

 

9. The last and final step is putting some thread lock adhesive on the caliper fixing bolts.

⚠️ At this point, don't loosen both caliper fixing bolts at the same time. Make sure that both are tight.

Loosen only one of the caliper fixing bolts and carefully remove it. Apply a small drop of thread lock adhesive (doesn't take much) to the threads and re-insert the bolt. Tighten/torque as necessary.

Repeat the procedure for the second bolt.