GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Check the LH high beam headlamp bulb for a damaged or open filament.
  2. Check the LH Headlamp connector to verify that the seal is not missing or damaged.

Is the headlamp bulb and connector OK?

--

Go to Step 2

Go to Step 9

2

  1. Turn the headlamp dimmer switch to the HIGH position.
  2. Using a test light, backprobe between the left headlamp harness connector C141 terminal F and ground.

Does the test light illuminate?

--

Go to Step 5

Go to Step 4

3

Repair a poor connection or an open in circuit 11 between the underhood accessory wiring junction block harness connector C3 terminal A11 and the left headlamp harness connector C141 terminal F.

Has the repair been made?

--

Go to Headlight System Check

--

4

Using a test light, backprobe between the underhood accessory wiring junction block harness connector C3 terminal A11 and ground.

Does the test light illuminate?

--

Go to Step 3

Go to Step 8

5

Using a test light, to backprobe between the left headlamp harness connector C141 terminal F and terminal G.

Does the test light illuminate?

--

Go to Step 7

Go to Step 6

6

Repair a poor connection or an open in circuit 1350 between the left headlamp wiring harness connector terminal G and G101.

Has the repair been made?

--

Go to Headlight System Check

--

7

Replace the left headlamp. Refer to Headlamp Replacement .

Has the repair been made?

--

Go to Headlight System Check

--

8

Replace the underhood wiring junction block. Refer to Accessory Wiring Junction Block Replacement in Body Front End.

Has the repair been made?

--

Go to Headlight System Check

--

9

Replace the damaged component.

Has the repair been made?

--

Go to Headlight System Check

--