Schematic Reference: Exterior Lights Schematics

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

1. Turn ON the ignition, with the engine OFF.
2. Observe the stop lamps.
3. Depress and release the brake pedal.

Do the stop lamps operate properly?

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

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the stop lamp switch.
3. Connect a test lamp between the battery positive voltage circuit of the stop lamp switch and a good ground.
4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 4

Go to Step 10

1. Turn OFF the ignition.
2. Connect a 20-amp fused jumper between the stop lamp switch battery positive voltage circuit of the stop lamp switch and the stop lamp supply voltage circuit of the stop lamp switch.
3. Turn ON the ignition, with the engine OFF.

Do all of the stop lamps illuminate?

Go to Step 7

Go to Step 5

1. Disconnect the inoperative stop lamp bulb.
2. Connect a test lamp between the stop lamp supply voltage circuit of the inoperative stop lamp bulb and the ground circuit of the inoperative stop lamp bulb.

Does the test lamp illuminate?

Go to Step 8

Go to Step 6

Test the stop lamp supply voltage circuit of the stop lamp bulb for a high resistance or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

Inspect for poor connections at the inoperative stop lamp bulb. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

Repair the open or high resistance in the stop lamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

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Repair the high resistance, open or short to ground in the battery positive voltage circuit of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

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Replace the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Did you complete the replacement?

Go to Step 13

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Replace the inoperative stop lamp bulb.

Did you complete the replacement?

Go to Step 13

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2