Schematic Reference: Exterior Lights Schematics

Did you perform the Lighting Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

Verify the fault is present.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

1. Turn OFF the ignition.
2. Depress the brake pedal and inspect the brake lamps.

Do the brake lamps light?

Go to Step 4

Go to Stop Lamps Inoperative

Remove and inspect the CHMSL fuse. Refer to Testing for Short to Ground in Wiring Systems.

Is the fuse open?

Go to Step 9

Go to Step 5

1. Re-install the fuse.
2. Remove the CHMSL and inspect the light blub filaments.

Are the filaments open?

Go to Step 10

Go to Step 6

Connect a test lamp between the lamp ground circuit of the CHMSL to a battery positive voltage circuit . Refer to Testing for Continuity in Wiring Systems.

Does the test lamp illuminate?

Go to Step 8

Go to Step 7

Repair the open lamp ground circuit between the lamp and the ground. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

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Repair the open in the fused trailer CHMSL feed circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

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Repair the short to ground in the fused trailer CHMSL feed circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

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Replace lamps as necessary.

Did you complete the repair?

Go to Step 11

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3