Taylor-Dunn MB-238-00, Operation, T Roubleshooting And Replacement Parts Manual

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Electrical Troubleshooting
Troubleshooting Page 24
Connect a volt meter from battery negative to the Violet/Black wire at the electric brake harness
plug.
If the voltage is less than battery volts then:
•
Check wiring to the key switch and continue troubleshooting at test #4.2.
If the voltage equals battery volts then:
Connect a volt meter across the Violet/Black wire and the Blue wire at the electric brake harness
plug. 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 pigtail harness to the electric brake is broken or the electric brake has failed. Remove
the brake and repair or replace as required.
If the test is bad then:
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.
The electric brake is part of the vehicle braking system. Do not operate
a vehicle with the electric brake bypassed or disabled unless the
system is being tested for faults. Operating a vehicle with the brake
bypassed or disabled may result in severe personal injury or property
damage.