Taylor-Dunn B0-254-48 Operation, T Roubleshooting And Replacement Parts Manual page 171

Connect a volt meter across the Violet/Black wire at the electric brake harness plug and Pin #9 at the logic
card connector. The voltage should start at approximately 24 volts, then drop to approximately 15 volts
after about 0.5 seconds.
If the test is good then:
• The blue wire from the electric brake harness plug to pin #9 on the logic card connector is
broken. Stop trouble shooting here and repair the problem. When the repair is completed,
completely retest the vehicle before lowering the drive wheels to the ground.
If the test is bad then:
• The logic card is not releasing the brake. This could be a result of:
-Improper operation of the vehicle.
- fault in the vehicles wiring or switches.
-A fault in the speed controller.
-Incorrect programming.
-A failed speed controller.
Disconnect the electric brake harness connector and connect the electric brake to a 24-volt source. This
should release the brake and allow you to troubleshoot the vehicles control system. Return to the beginning
of the troubleshooting section and continue.
If the brake does not release then:
•
The electric brake has failed. Remove the brake and repair or replace the brake as required.
Stop trouble shooting here and repair the problem. When the repair is completed, completely
retest the vehicle before lowering the drive wheels to the ground.
After any repairs are made, completely retest
the vehicle before lowering the drive wheels to
the ground. Failure to retest the vehicle could
result in unexpected movement of the vehicle
resulting in injury or property damage.
Electrical Troubleshooting
This troubleshooting guide is written in
sequential order. All tests must be performed in
the order that they are written. Starting in the
middle or skipping sections when not instructed
to do so may lead to invalid test results.
Sevcon Troubleshooting
Page 17