GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the headlamp switch.
  2. Turn the headlamp dimmer switch to the LOW position.
  3. Using a test light, frontprobe between the headlamp switch harness connector terminal D to ground.

Does the test light illuminate?

--

Go to Step 2

Go to Step 5

2

Using a test light, probe between the headlamp switch harness connector terminal D to ground.

Does the test light illuminate?

--

Go to Step 3

Go to Step 4

3

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Has the repair been made?

--

Go to Headlight System Check

--

4

Repair a poor connection or an open in circuit 1750 between the headlamp switch and the harness connector terminal A and G201.

Has the repair been made?

--

Go to Headlight System Check

--

5

  1. Reconnect the headlamp switch.
  2. Using a test light, backprobe between connector C201 terminal A3 and ground.

Does the test light illuminate?

--

Go to Step 6

Go to Step 7

6

Repair a poor connection or an open in circuit 10 between the harness connector C201 terminal A3 and S221.

Has the repair been made?

--

Go to Headlight System Check

--

7

Using a test light, backprobe between connector C201 terminal A2 and ground.

Does the test light illuminate?

--

Go to Step 8

Go to Step 9

8

Replace the headlamp dimmer switch. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle .

Has the repair been made?

--

Go to Headlight System Check

--

9

Using a test light, backprobe between the underhood accessory wiring junction block harness connector C2 terminal F10 to ground.

Does the test light illuminate?

--

Go to Step 11

Go to Step 10

10

Replace the underhood accessory wiring junction block. Refer to Accessory Wiring Junction Block Replacement .

Has the repair been made?

--

Go to Headlight System Check

--

11

Repair a poor connection or an open in circuit 1201 between the underhood accessory wiring junction block harness connector C2 terminal F10 and connector C201 terminal A2.

Has the repair been made?

--

Go to Headlight System Check

--