F 150 4WD V8-4.6L VIN 8 (2010)
Trailer Lamps: Initial Inspection and Diagnostic Overview
Special Tools Used With Diagnostics
Trailer Lamps
Principles of Operation
Trailer Lamps
Principles of Operation
The trailer lamps and battery charge are supplied power by relays that are energized to correspond with the exterior lighting functions of the vehicle.
If the vehicle is not equipped with the factory manufactured Trailer Brake Control (TBC) module, the vehicle supplies circuitry to support the
installation of an aftermarket TBC module (installed by the customer). To support the aftermarket TBC module, the vehicle circuitry only supplies
voltage, ground, stoplamp switch input and a brake controlling circuit to the trailer tow connector. The trailer electric brakes themselves are controlled
by the aftermarket TBC module and not the vehicle.
For diagnostics and a description of the factory manufactured TBC system, refer to Trailer Brake Control Module.
Inspection and Verification
Trailer Lamps
Inspection and Verification
1. Verify the customer concern.
2. Verify the exterior lighting system of the vehicle is operating correctly. If not, refer to the appropriate pinpoint test.
3. Visually inspect for obvious signs of electrical damage.
Visual Inspection Chart
