Hazard Warning Lamps: Testing and Inspection

When diagnosing the turn signal or hazard warning circuits, remember that high generator output can burn out bulbs rapidly and repeatedly If this is a problem on the vehicle being diagnosed, refer to Charging System for further diagnosis of a possible generator overcharging condition.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIR BAGS AND SEAT BELTS/AIR BAGS 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.

1. Turn the ignition switch to the On position. Actuate the turn signal lever or the hazard warning button. Observe the turn signal indicator lamp(s) in the instrument cluster. If the flash rate is very high, check for a turn signal bulb that is not lit or is very dimly lit. Repair the circuits to that lamp or replace the faulty bulb, as required. Test the operation of the turn signal and hazard warning systems again. If the turn signal indicator(s) fail to light, go to Step 2.
2. Turn the ignition switch to the Off position. Check the turn signal fuse in the junction block and/or the hazard warning fuse in the Power Distribution Center (PDC). If OK, go to Step 3. If not OK, repair the shorted circuit or component as required and replace the faulty fuse(s).
3. Turn the ignition switch to the On position to check for battery voltage at the turn signal fuse in the junction block; or, leave the ignition switch in the Off position to check for battery voltage at the hazard warning fuse in the PDC. If OK, go to Step 4. If not OK, repair the open circuit as required.
4. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Unplug the combination flasher from the junction block and replace it with a known good unit. Connect the battery negative cable. Test the operation of the turn signal and hazard warning systems. If OK, discard the faulty combination flasher. If not OK, remove the test flasher and go to Step 5.
5. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output circuit cavity for the combination flasher in the junction block. If OK, go to Step 6. If not OK, repair the open circuit to the turn signal fuse as required.
6. Turn the ignition switch to the Off position. Check for battery voltage at the fused B(+) circuit cavity for the combination flasher in the junction block. If OK, go to Step 7. If not OK, repair the open circuit to the hazard warning fuse as required.
7. Disconnect and isolate the battery negative cable. Check for continuity between the ground circuit cavity for the combination flasher in the junction block and a good ground. There should be continuity. If OK, go to Step 8. If not OK, repair the circuit to ground as required.
8. Unplug the multi-function switch wire harness connector as described. Check for continuity between the combination flasher hazard signal circuit cavities in the junction block and in the multi-function switch wire harness connector. There should be continuity. If OK, go to Step 9. If not OK, repair the open circuit as required.
9. Check for continuity between the combination flasher turn signal circuit cavities in the junction block and in the multi-function switch wire harness connector. There should be continuity. If OK, test the mufti-function switch as described. If not OK, repair the open circuit as required.