Taylor-Dunn RE-380-36, Operator'S And Service Manual, Page: 147 / 260

Sevcon Troubleshooting
Page 7
Electrical Troubleshooting
Test 2. TESTING THE MOTOR
Disconnect both of the battery leads during any maintenance or
before disconnecting any electrical component or wire. Failure to do
so may cause property damage and/or serious bodily injury.
NOTE: Special and expensive motor testing equipment is required in order to accurately measure motor armature
or field resistance. In most cases, this equipment is not required in order to determine if a motor is faulty.
The majority of motor failures are due to an open circuit in the field or armature windings. If the symptom
of the vehicle is “not running with NO motor current” then a simple continuity test of each winding is all
that is required to determine if the motor is at fault.
TEST 2.1:
Check the motor field continuity from the motor
F1 to the motor F2 terminals.
If the resistance is close to values given in
the motor specification table, then skip
ahead to test #2.2. (The motor specification
table can be found in the “Motor Service”
section).
If the test indicates an open circuit, then
repair or replace the motor.
Test continuity from F1 to the frame of the motor.
Any reading other than an open circuit
indicates a short in the motor.
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.
STOP
TEST 2.2:
Check the continuity from the motor A1 to the A2
terminals.
If the resistance is close to values given in
the motor specification table, then go to test
#2.3.
If the test indicates high resistance or an
open circuit, then repair or replace the motor.
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.
STOP
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.
Motor shown in illustrations is typical of a standard motor.
The terminal configuration of your motor may be different.