Brake Light Switch: Testing and Inspection

GENERAL INFORMATION
Stop lamp switch operation can be tested with an ohmmeter. The ohmmeter is used to check continuity between the pin terminals at different plunger positions.

NOTE: The switch wire harness must be disconnected before testing switch continuity.

SWITCH CIRCUIT IDENTIFICATION

Stop Lamp Switch Terminal Identification:

- Terminals 1 and 2 are for the RWAL/ABS module and Powertrain Control Module (PCM) circuit.
- Terminals 5 and 6 are for the stop lamp circuit.
- Terminals 3 and 4 are for the speed control circuit.

SWITCH CONTINUITY TEST
1. Check continuity between terminal pins 5 and 6 as follows:
a. Pull plunger all the way out to fully extended position.
b. Attach test leads to pins 5 and 6 and note ohmmeter reading.
c. If continuity exists, proceed to next test. Replace switch if meter indicates lack of continuity (shorted or open).
2. Check continuity between terminal pins 1 and 2 and pins 3 and 4 as follows:
a. Push switch plunger inward to fully retracted position.
b. Attach test leads to pins 1 and 2 and note ohmmeter reading.
c. If continuity exists, switch is OK. Replace switch if meter indicates lack of continuity (switch is open).