For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Press down the brake pedal. Do all of the stop lamps illuminate? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3
3 | Are all lamps inoperative? | Go to Step 5 | Go to Step 4
4 | Test the voltage supply and ground circuits of the inoperative lamp or high mounted stop lamp for an open or high resistance. Did you find and correct the condition? | Go to Step 14 | Go to Step 9
5 |

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

6 | Connect a 10-amp fused jumper wire between the battery positive voltage circuit of the brake switch and the stop lamp supply voltage circuit. Do the stop lamps illuminate? | Go to Step 7 | Go to Step 11
7 | Inspect for poor connections at the harness connector of the brake switch. Did you find and correct the condition? | Go to Step 14 | Go to Step 8
8 | Inspect the brake switch for proper adjustment. Did you find and correct the condition? | Go to Step 14 | Go to Step 12
9 | Inspect for poor connections at the harness connector of the inoperative lamp or high mounted stop lamps. Did you find and correct the condition? | Go to Step 14 | Go to Step 13
10 | 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 | --
11 | Repair an open or high resistance in the stop lamp supply voltage circuit. Did you complete the repair? | Go to Step 14 | --
12 | Replace the brake switch. Did you complete the replacement? | Go to Step 14 | --
13 | Replace the bulb or high mounted stop lamp assembly. Did you complete the replacement? | Go to Step 14 | --
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3