Operation CHARM: Car repair manuals for everyone.

Headlamp Relay: Testing and Inspection

The headlamp (or security) relay and the horn relay are located in the Power Distribution Center (PDC) in the engine compartment. Each of these relays can be tested as described in the following procedure, however the circuits they are used in do vary.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIRBAGS AND SEAT BELTS/AIRBAGS BEFORE ATTEMPTING ANY STEERING WHEEL,STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

Relay Terminals:




Remove the relay from the PDC as described in this information to perform the following tests:

1. A relay in the de-energized position should have continuity between terminals 87A and 30, and no continuity between terminals 87 and 30. If OK, go to Step 2. If not OK, replace the faulty relay.
2. Resistance between terminals 85 and 86 (electromagnet) should be 75 ± 5 ohms. If OK, go to Step 3. If not OK, replace the faulty relay.
3. Connect a battery to terminals 85 and 86. There should now be continuity between terminals 30 and 87, and no continuity between terminals 87A and 30. If OK, test the relay circuits. If not OK, replace the faulty relay.