F 150 4WD V8-4.6L VIN 8 (2010)
Brake Lamp: Pinpoint Tests
Pinpoint Test I: All The Stoplamps Are Inoperative
Stoplamps
Pinpoint Tests
Pinpoint Test I: All The Stoplamps Are Inoperative
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. See: Diagrams/Electrical
Diagrams/Diagrams By Number
Normal Operation
The stoplamp switch is supplied voltage from the Battery Junction Box (BJB). When the brake pedal is applied, the stoplamp switch routes voltage to the
Smart Junction Box (SJB) and the high mounted stoplamp.
This pinpoint test is intended to diagnose the following:
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Fuse
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Wiring, terminals or connectors
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Stoplamp switch
PINPOINT TEST I: ALL 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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I1 CHECK FOR VOLTAGE TO THE STOPLAMP SWITCH
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Ignition OFF.
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Disconnect: Stoplamp Switch C278.
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Measure the voltage between the stoplamp switch C278-1, circuit SBB46 (BN/RD), harness side and ground.
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Is the voltage greater than 10 volts?
Yes
GO to I2.
No
VERIFY the BJB fuse 46 (15A) is OK. If OK, REPAIR circuit SBB51 (BU/RD) 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. See: Diagrams/Electrical Diagrams/Diagrams By Number
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I2 BYPASS THE STOPLAMP SWITCH
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Connect a fused jumper wire between the stoplamp switch C278-1, circuit SBB46 (BN/RD), harness side and the stoplamp switch C278-4, circuit
CCB08 (VT/WH), harness side.