GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Review the underhood lamp operation and perform the necessary inspections.

Did you complete the system review and inspection?

--

Go to Step 2

Go to Symptoms

2

Attempt to operate the underhood lamp and reel lamp.

Does the system operate normally?

--

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

Go to Step 3

3

  1. Open the hood.
  2. Ensure that the lamp is correctly mounted.
  3. Disconnect the underhood lamp connector.
  4. Measure the voltage at cavity A.

Is the measurement equal to battery voltage?

B+

Go to Step 5

Go to Step 4

4

Repair the open CKT 740 (ORN) between the HORN fuse and the underhood lamp connector.

Did you complete the repair?

--

Go to Step 8

--

5

Test continuity between ground and cavity B of the underhood lamp connector.

Is continuity present?

--

Go to Step 7

Go to Step 6

6

Repair the open CKT 150 (BLK) between the underhood lamp and ground.

Did you complete the repair?

--

Go to Step 8

--

7

Replace the underhood lamp bulb.

Did you complete the repair?

--

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3