D 350 Pickup V8-360 5.9L VIN W (1984)
Power Door Lock Relay: Testing and Inspection
To test the relay, move either of the front lock knobs to the lock and unlock positions. An audible clicking sound should be heard from under the dash
near the steering column support. If the sound is heard while operating one knob but not the other, a defective switch or wiring may be at fault. If a
clicking sound is not heard, locate the relay and test as follows:
1. Check for power by back probing the LG wire at the relay.
^
If power is present, go to step 2.
^
If power is not present, check the circuit breaker and the wire between the relay and the circuit breaker.
2. Back probe the OR wire at the relay and move the lock knob to the lock position. Battery voltage should be momentarily present, indicating that
the relay operates in the lock position.
^
If power is present go to step 4.
^
If power is not present, go to step 3.
3. Backprobe the VT wire and move the lock knob to the lock position.
^
If power is present, the relay is defective.
^
If power is not present, the door switch or wiring may be defective.
4. Backprobe the LB wire at the relay and move the lock knob to the unlock position. Battery voltage should be momentarily present, indicating that
the relay operates in the unlock position.
^
If power is present, the relay is operating properly.
^
If power is not present, go to step 5.
5. Backprobe the LG wire and move the lock knob to the unlock position.
^
If power is present, the relay is defective.
^
If power is not present, the door switch or wiring may be defective.
