Taylor-Dunn SC-011-59 Operation, T Roubleshooting And Replacement Parts Manual page 102

Electrical Troubleshooting
Control Wire inputs Test
Connect a voltmeter across the Solenoid
Negative Buss Bar and battery positive.
•
If the voltage is not at battery volts then
check the wiring to battery negative and
the negative circuit breaker. 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.
Connect a voltmeter across the ISO solenoid coil
terminals.
Close all interlock switches and turn the
Key Switch ON.
Depress the accelerator pedal to engage
MS-1 only.
• If the voltage is not at battery volts then
go to the Key Switch sequence.
• If the voltage is at battery volts and the
ISO solenoid does not pick up (click) then
the ISO solenoid has failed. 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.
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.
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.
Main Sequence
The voltage shown is for illustration
only. The actual voltage may vary.
Solenoids are shown for reference
only. The type of solenoid in your
truck may look different
+
_
FWD
The voltage shown is for illustration
only. The actual voltage may vary.
Solenoids are shown for reference
only. The type of solenoid in your
truck may look different
+
_
FWD
Page 6
Main Battery
Positive
REV
ISO
REV
ISO