Pinpoint Test H: The Stoplamps Are Inoperative

Stoplamps

Pinpoint Test H: The Stoplamps Are Inoperative

Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number

Normal Operation

The Battery Junction Box (BJB) supplies voltage to the stoplamp switch through circuit 1119 (RD). When the brake pedal is applied, the stoplamp switch closes and routes voltage to the stoplamps through circuit 10 (LG/RD).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Fuse
- Stoplamp switch



PINPOINT TEST H: THE STOPLAMPS ARE INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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H1 CHECK CIRCUIT 1119 (RD) FOR AN OPEN


- Ignition OFF.
- Disconnect: Stoplamp Switch C278.
- Measure the voltage between the stoplamp switch C278-1, circuit 1119 (RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to H2.

No
VERIFY the BJB fuse 14 (20A) is OK. If OK, REPAIR the circuit for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.

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H2 CHECK CIRCUIT 10 (LG/RD) FOR AN OPEN


- Connect a fused jumper wire between the stoplamp switch C278-1, circuit 1119 (RD), harness side and the stoplamp switch C278-2, circuit 10 (LG/RD), harness side.




- Do the stoplamps illuminate?

Yes
REMOVE the jumper wire. INSTALL a new stoplamp switch. REFER to Stoplamp Switch Service and Repair. TEST the system for normal operation.

No
REMOVE the jumper wire. REPAIR the circuit. TEST the system for normal operation.

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