Taylor-Dunn SS-025-34 Operation, Maintenance, And Replacement Parts Manual page 120

Curtis PMC Troubleshooting
SOLENOIDS
There is a very slight possibility that a failure in the motor could cause these symptoms. Perform
the tests covered in the MOTOR section first. If the motor is OK, continue with the following tests.
Remove the wires from the 'S1' and 'S2' terminals on the motor. Remove the wire from the
'M-' terminal on the PMC control. Make sure none of these wires can come into electrical contact
with the frame or any other wire.
Reconnect the batteries.
With the key-switch on and the forward and reverse switch in neutral, perform the
following tests:
•
Check continuity from the motor 'A2' terminal to the wire that was connected to the motor
'S1' terminal. DO NOT make this test to the
'S1" terminal, just the wire. Refer to Solenoid
Figure 1.
If you do not know how to test for continuity, refer
test to a qualified technician.
•
This should be an open circuit, if it reads as a
short, then one of the following has occurred:
A) The reverse solenoid is shorted.
B) The wire connected to the motor 'S1' terminal
is shorted to the wire connected to the motor
'A2' terminal.
C) The wire connected to the motor 'S1' terminal
is shorted to the wire connected to the PMC
'A2' terminal.
Page 26
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.