One Window Fails to Operate
Failure of one window to operate in
either direction may be due to
trouble in the circuit breaker, the
door relay, the switch, the motor, or
the associated wiring.
First check for voltage at the circuit
breaker terminal for the window in
question. No voltage at this point
indicates a defective circuit breaker
which should be replaced. But if
voltage is available at the circuit
breaker, the following checks must
Check for voltage at the No. 3
terminal of the door relay. No
voltage at this terminal indicates
defective wiring between the relay
and the circuit breaker. Repairing
or replacing the wire should cure
If there is voltage at the No. 3 terminal of the relay, use a clip lead to short
No. 1 and then No. 2 terminal of the relay to ground. If the window now
operates properly, the wiring to the switch or the switch itself is defective.
Repair or replace as necessary. If the window still will not operate, a relay
and motor test is necessary.
RELAY AND MOTOR TEST
To perform this test, listen for the relays to click when the No. ¹ and No.
2 terminals are shorted to ground. If the relays do not click, the relay
assembly is defective and must be replaced.