Taylor-Dunn B0-248-TT, Operation, T Roubleshooting And Replacement Parts Manual, Page: 124 / 204

Maintenance, Service, and Repair
Electrical Troubleshooting
Page 14
FREEWHEEL DIODE
Remove the wires from the ‘B+’ and ‘M-’ terminals on the controller and perform the following
test:
Using the diode test function on the DMM check for the presence of a diode across the ‘B+’ and
‘M-’ terminals on the controller.
If you do not know how to test for a diode, refer test to a qualified technician.
•
If the diode is open or shorted, then the controller must be replaced. Stop troubleshooting
here and repair the problem.
PLUGGING DIODE
Remove the wires from the ‘B+’ and ‘A2’ terminals on the controller and perform the following
test:
Using the diode test function on the DMM check for the presence of a diode across the ‘B+’ and
‘A2’ terminals on the controller.
If you do not know how to test for a diode, refer test to a qualified technician.
•
If the diode is open or shorted, then the controller must be replaced. Stop troubleshooting
here and repair the problem.
1. Make sure the key-switch is in the “OFF” position, then remove the key.
2. Place the forward-reverse switch in the center “OFF” position.
3. Set the park brake.
4. Place blocks under the front wheels to prevent vehicle movement.
5. Disconnect the main positive and negative cables at the batteries.
The rear drive wheels may rotate during some of the following tests. Block the
front wheels, raise the rear drive wheels off the ground, and support the vehicle
with jack stands. Failure to do so may cause the vehicle to move and cause
severe bodily injury and/or property damage.
Rotating rear drive wheels are a potential hazard. Keep hands, arms, legs and
loose clothing away from the rear drive wheels while conducting tests. Failure
to do so may cause serious bodily injury.
1. Make sure the key-switch is in the “OFF” position, then remove the key.
2. Place the forward-reverse switch in the center “OFF” position.
3. Set the park brake.
4. Place blocks under the front wheels to prevent vehicle movement.
5. Disconnect the main positive and negative cables at the batteries.
The rear drive wheels may rotate during some of the following tests. Block the
front wheels, raise the rear drive wheels off the ground, and support the vehicle
with jack stands. Failure to do so may cause the vehicle to move and cause
severe bodily injury and/or property damage.
Rotating rear drive wheels are a potential hazard. Keep hands, arms, legs and
loose clothing away from the rear drive wheels while conducting tests. Failure
to do so may cause serious bodily injury.