Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Verify the brake pedal is not being pressed down.
2. Verify the trailer hand brake is not applied.

Are the stop lamps OFF?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Disconnect the stop lamp switch.

Are the stop lamps illuminated?

Go to Step 4

Go to Step 7

Is the vehicle being worked on equipped with air brakes?

Go to Step 5

Go to Step 6

Disconnect the trailer stop lamps switch.

Are the stop lamps illuminated?

Go to Step 6

Go to Step 9

Test the brake switch input circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

Inspect the stop lamp switch for proper adjustment, if the vehicle has hydraulic brakes. Refer to Stop Lamp Switch Adjustment .

Did you find and correct the condition?

Go to Step 11

Go to Step 8

Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 11

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Replace the trailer stop lamps switch. Refer to Trailer Stop Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 11

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Replace the hazard flasher.

Did you complete the replacement?

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