Turn Signal and Hazard Warning System Test

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

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIRBAGS AND SEAT BELTS/AIRBAGS BEFORE ATTEMPTING 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 hazard warning button. Observe the turn indicator lamp(s) in the instrument cluster. If the flash rate is very high, check for a turn signal lamp that is not lit. Replace that lamp or repair the circuits to that lamp, as required. Test the operation of the system again. If the turn indicator(s) fail to light, go to Step 2.
2. Remove and inspect the turn signal fuse in the fuse block, and/or the turn signal and hazard warning fuses in the Power Distribution Center (PDC). Replace the faulty fuse(s), if required, and go to Step 3.
3. Remove the combination flasher from the connector tape to the steering column wire harness and replace it with a known good flasher. 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 4.
4. With the ignition switch in the ON position, check for battery voltage at the fused ignition switch output (run) circuit cavity for the combination flasher. If OK, go to Step 5. If not OK, repair the open circuit between the ignition switch and the combination flasher as required.
5. With the ignition switch in the OFF position, check for battery voltage at the fused B (+) circuit cavity of the combination flasher connector. Locate the combination flasher connector taped to the steering column wire harness. If OK, go to Step 6. If not OK, repair the open circuit to the PDC as required.
6. With the ignition switch in the OFF position, check for continuity between the ground circuit cavity of the combination flasher connector and a good ground. There should be continuity. If OK, go to Step 7. If not OK, repair the circuit to ground as required.
7. Check for continuity between the combination flasher output circuit cavities of the connector and the multi-function switch connector. There should be continuity. If OK, test the multi-function switch as described. If not OK, repair the open circuit as required.