Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Brake Light Switch: Testing and Inspection




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

Switch Circuit Identification
- Terminals 1 and 2: brake sensor circuit
- Terminals 3 and 4: speed control circuit
- Terminals 5 and 6: brake lamp circuit

Switch Continuity Test

NOTE: Disconnect switch harness before testing continuity.

With the switch plunger retracted, attach the test leads to terminal pins 1 and 2. Replace switch if meter indicates no continuity.

With the switch plunger retracted, attach the test leads to terminal pins 3 and 4. Replace switch if meter indicates no continuity.

With the switch plunger extended, attach the test leads to terminal pins 5 and 6. Replace switch if meter indicates no continuity.