GM Service Manual Online
For 1990-2009 cars only

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Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn OFF the ignition.
  2. Turn the headlamp switch to the PARK position.

Do the park lamps operate properly?

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

Go to Step 3

3

Are all the park lamps inoperative?

Go to Step 10

Go to Step 4

4

Are all the front park lamps inoperative?

Go to Step 8

Go to Step 5

5

Are all the rear park lamps inoperative?

Go to Step 9

Go to Step 6

6

  1. Remove the inoperative park lamp bulb.
  2. Connect a test lamp between the park lamp supply voltage circuit of the inoperative park lamp bulb and ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 17

7

Connect a test lamp between the ground circuit of the inoperative park lamp and the park lamp supply voltage circuit of the inoperative park lamp bulb.

Does the test lamp illuminate?

Go to Step 14

Go to Step 18

8

Check the FRONT PARK fuse for an open.

Is the FRONT PARK fuse open?

Go to Step 19

Go to Step 12

9

Check the TAIL LAMP LIC LAMP fuse for an open.

Is the TAIL LAMP LIC LAMP fuse open?

Go to Step 20

Go to Step 16

10

  1. Disconnect the headlamp switch.
  2. Using a test lamp connected to ground, probe the battery positive voltage supply circuit of the headlamp switch.

Does the test lamp illuminate?

Go to Step 11

Go to Step 21

11

Connect a fused jumper between the battery positive voltage circuit and the park lamps supply voltage circuit of the headlamp switch connector.

Do the park lamps illuminate?

Go to Step 13

Go to Step 22

12

Test the park lamps supply voltage circuit of the front park lamps for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 25

Go to Step 15

13

Inspect for poor connections at the harness connector of the headlamp 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 25

Go to Step 23

14

Inspect for poor connections at the harness connector of the inoperative park lamp bulb. 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 25

Go to Step 24

15

Repair a high resistance or an open in the ground circuit of the front park lamps. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

16

Repair the high resistance or open in the park lamp supply voltage circuit of the rear park lamps. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

17

Repair the high resistance or open in the park lamp supply voltage circuit of the inoperative park lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

18

Repair the high resistance or open in the ground circuit of the inoperative park lamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

19

Repair the short to ground in the park lamps supply voltage circuit of the front park lamps. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

20

Repair the short to ground in the park lamps supply voltage circuit of the rear park lamps. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

21

Repair the high resistance or open in the battery positive supply circuit of the headlamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

22

Repair the high resistance or open in the park lamps supply voltage circuit of the headlamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 25

--

23

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 25

--

24

Replace the inoperative park lamp bulb.

Did you complete the replacement?

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2