Symptom Chart: Trailer Lamps

Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to DIAGNOSTIC METHODS for information regarding Ford-specific diagnostic practices.

SYMPTOM CHART

Condition	Possible Sources	Actions
A module does not respond to the scan tool	Fuse Wiring, terminals or connectors Module	REFER to SYMPTOM CHART: COMMUNICATION NETWORK .
All the trailer lamps are inoperative	Wiring, terminals or connectors Trailer tow connector Trailer	REFER to Diagnostic Routine AH: All The Trailer Lamps Are Inoperative .
The trailer stop-turn lamp is inoperative	Fuse Wiring, terminals or connectors Trailer tow stop/turn lamp relay Trailer tow connector Trailer	REFER to Diagnostic Routine AI: The Trailer Stop-Turn Lamps Are Inoperative .
The trailer parking lamps are inoperative	Fuse Wiring, terminals or connectors Trailer tow parking lamp relay Trailer tow connector Trailer	REFER to Diagnostic Routine AJ: The Trailer Parking Lamps Are Inoperative .
The trailer reversing lamps are inoperative	Fuse Wiring, terminals or connectors Trailer tow reversing lamp relay Trailer tow connector Trailer	REFER to Diagnostic Routine AK: The Trailer Reversing Lamps Are Inoperative .
The trailer lamps are on continuously	Wiring, terminals or connectors Trailer tow relay Trailer	REFER to Diagnostic Routine AL: The Trailer Lamps Are On Continuously .
The trailer battery charging is inoperative or operates with the ignition off	Fuse Wiring, terminals or connectors Trailer tow battery charge relay Trailer tow connector Trailer	REFER to Diagnostic Routine AM: The Trailer Battery Charging Is Inoperative Or Operates With The Ignition Off .
The trailer electric brakes are inoperative or always applied	Fuse Wiring, terminals or connectors TBC module Trailer tow connector Trailer BCM	REFER to Diagnostic Routine AN: The Trailer Electric Brakes Are Inoperative Or Always Applied .