GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the exterior lighting description and operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Turn ON the ignition switch, with the engine OFF.
  2. Place the turn signal switch in the left turn and right turn positions.

Do the turn signal lamps operate properly?

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

Go to Step 3

3

  1. Disconnect the hazard lamps flasher.
  2. Probe the battery positive voltage circuit of the hazard lamps flasher with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 10

4

Connect the test lamp between the battery positive voltage circuit of the hazard lamps flasher and the hazard lamps flasher ground circuit.

Does the test lamp illuminate?

Go to Step 5

Go to Step 11

5

  1. Connect a 20 amp fused jumper wire between the battery positive voltage circuit of the hazard lamps flasher and the turn signal flasher signal circuit of the hazard lamps flasher.
  2. Place the turn signal switch in the left turn position.

Does the left turn signal lamp illuminate?

Go to Step 8

Go to Step 6

6

  1. Leave the fused jumper wire connected.
  2. Disconnect the turn signal switch.
  3. Probe the turn signal flasher signal circuit of the turn signal switch with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 12

7

  1. Leave the jumper wire connected.
  2. Connect a 20 amp fused jumper wire between the turn signal flasher signal circuit of the turn signal switch and the left turn signal lamp supply voltage circuit of the turn signal switch.

Does the left turn signal lamp illuminate?

Go to Step 9

Go to Step 13

8

Inspect for poor connections at the hazard lamps flasher. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 14

9

Inspect for poor connections at the harness connector of the turn signal switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 15

10

Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the hazard lamps flasher. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

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11

Repair an open or high resistance in the hazard lamps flasher ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

12

Repair an open, high resistance, or short to ground in the turn signal flasher signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

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13

Repair an open in the turn signal lamps ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

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14

Replace the hazard lamps flasher. Refer to Hazard and Turn Signal Flasher Replacement .

Did you complete the replacement?

Go to Step 16

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15

Replace the turn signal switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column-Standard.

Did you complete the replacement?

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3