Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

Press down the brake pedal.

Do all of the brake lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Are all lamps inoperative?

Go to Step 5

Go to Step 4

Test the voltage supply and ground circuits of the inoperative lamp or high mounted brake lamp for an open or high resistance.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

1. Disconnect the brake switch.
2. Probe the battery positive voltage circuit of the brake switch with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 10

Connect a 10-amp fused jumper wire between the battery positive voltage circuit of the brake switch and the brake lamp supply voltage circuit.

Do the brake lamps illuminate?

Go to Step 7

Go to Step 11

Inspect for poor connections at the wiring harness plug of the brake switch.

Did you find and correct the condition?

Go to Step 14

Go to Step 8

Inspect the brake switch for proper adjustment.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

Inspect for poor connections at the wiring harness plug of the inoperative lamp or high mounted brake lamps.

Did you find and correct the condition?

Go to Step 14

Go to Step 13

Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the brake switch.

Did you complete the repair?

Go to Step 14

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Repair an open or high resistance in the brake lamp supply voltage circuit.

Did you complete the repair?

Go to Step 14

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Replace the brake switch.

Did you complete the replacement?

Go to Step 14

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Replace the bulb or high mounted brake lamp assembly.

Did you complete the replacement?

Go to Step 14

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3