GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Lighting Systems?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition switch to the ON position.
  2. Move the turn signal lever to both the right and left turn signal positions.

Do both left and right turn signal lamps and/or indicators operate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Is only one lamp and/or indicator inoperative?

Go to Step 4

Go to Step 5

4

  1. Inspect the power supply or ground circuit for a poor connection or an open for the inoperative lamp and/or indicator. Refer to Circuit Testing in Wiring Systems.
  2. Repair the poor connection or open in the inoperative lamp. Refer to Wiring Repairs in Wiring Systems.
  3. If no fault is found, replace the inoperative lamp and/or indicator bulb.

Did you complete the repair?

System OK

--

5

Inspect the TRN-BU fuse.

Is the fuse open?

Go to Step 7

Go to Step 6

6

Repair the open in the Fuse Output-Ignition circuit between the fuse block and the turn/hazard flasher. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

--

7

  1. Disconnect the turn/hazard flasher connector.
  2. Turn the ignition switch to the ON position.
  3. Connect a test lamp between the ignition feed circuit of the turn/hazard flasher connector and ground.

Does the test lamp light?

Go to Step 9

Go to Step 8

8

Repair the open in the ignition feed circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

--

9

  1. Turn the LH turn signal or the RH turn signal to the ON position.
  2. Connect the fused jumper between the ignition feed circuit and the turn signal output circuit at the turn/hazard flasher connector.

Do the turn signal lamps and/or indicators illuminate but not flash?

Go to Step 10

Go to Step 11

10

Replace the turn/hazard flasher.

Is the repair complete?

System OK

--

11

  1. Reconnect the turn/hazard flasher connector.
  2. Disconnect the turn/hazard headlamp switch assembly.
  3. Connect a test lamp between the turn signal flasher output circuit of the turn/hazard headlamp switch assembly connector and ground.

Does the test lamp flash?

Go to Step 13

Go to Step 12

12

Repair the open in the turn signal flasher output circuit between the turn/hazard flasher and the turn/hazard headlamp switch assembly. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

System OK

--

13

Replace the turn/hazard headlamp switch assembly. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column.

Is the repair complete?

System OK

--