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 ELECTRICAL/CHARGING - DIAGNOSIS AND TESTING). If the problem being diagnosed is related to a failure of the turn signals to automatically cancel following completion of a turn, inspect the multi function switch for a faulty or damaged cancel actuator and inspect the turn signal cancel cam lobes on the clockspring mechanism for damage or improper installation. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. 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 switch or the hazard warning switch. 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. If the turn signal indicator(s) fail to light, go to Step 2.
2. Turn the ignition switch to the OFF position. Check the fused ignition switch (run-acc) fuse (Fuse 13 - 10 ampere) in the fuse block and/or the fused B(+) fuse (Fuse 7 - 20 ampere) 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. Check for battery voltage at the fused B(+) fuse (Fuse 7 - 20 ampere) in the PDC. If OK, go to Step 4. If not OK, repair the open fused B(+) circuit between the PDC and the battery as required.
4. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch (run-acc) fuse (Fuse 13 - 10 ampere) in the fuse block. If OK, go to Step 5. If not OK, repair the open fused ignition switch output (run-acc) circuit between the fuse block and the ignition switch as required.
5. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Remove the combination flasher from the left multi- function switch and replace it with a known good unit. Reconnect the battery negative cable. Turn the ignition switch to the ON position. Test the operation of the turn signal and hazard warning system. If OK, discard the faulty combination flasher. If not OK, remove the test flasher and go to Step 6.
6. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Disconnect the cross body wire harness connector for the left multi-function from the switch connector receptacle. Reconnect the battery negative cable. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run-acc) circuit cavity of the cross body wire harness connector for the left multi-function switch. If OK, go to Step 7. If not OK, repair the open fused ignition switch output (run-acc) circuit between the left multi-function switch and the fuse block as required.
7. Turn the ignition switch to the OFF position. Place the hazard warning switch in the ON position. Check for battery voltage at the hazard flasher feed circuit cavity in the cross body wire harness connector for the left multi-function switch. If OK, go to Step 8. If not OK, repair the open fused B(+) circuit between the left multi-function switch and the PDC as required.
8. Disconnect and isolate the battery negative cable. Check for continuity between the ground circuit cavity of the cross body wire harness connector for the left multi-function switch and a good ground. There should be continuity. If OK, proceed to the diagnosis for the left multi-function switch. (Refer to ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/LEFT MULTI-FUNCTION SWITCH - DIAGNOSIS AND TESTING). If not OK, repair the open ground circuit to ground (G300) as required.