Schematic Reference: Exterior Lights Schematics

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle Controls System in 2005 C/K Truck Service Manual

1. Block the wheels and set the parking brake.
2. Turn ON the ignition, with the engine OFF.
3. Place the gear selector in and out of the reverse position.

Does the backup alarm operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems in 2005 C/K Truck Service Manual

Go to Step 3

1. Turn OFF the ignition switch.
2. Disconnect the neutral start backup switch.
3. Turn ON the ignition, with the engine OFF.

Is the backup alarm on?

Go to Step 5

Go to Step 4

Inspect for poor connections at the harness connector of the backup lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems in 2005 C/K Truck Service Manual.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

Repair the short to voltage in the backup lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems in 2005 C/K Truck Service Manual.

Did you complete the repair?

Go to Step 7

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Replace the backup lamp switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transmission - Allison in 2005 C/K Truck Service Manual.

Did you complete the replacement?

Go to Step 7

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3