F 150 2WD Pickup V8-5.4L SOHC VIN 5 (2004)
Trailer Lamps: Initial Inspection and Diagnostic Overview
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 mechanical or electrical damage.
VISUAL INSPECTION CHART
Electrical
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Central junction box (CJB) fuse(s):
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10 (20A) (trailer tow parking and reversing lamps)
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36 (10A) (trailer tow RH stop/turn)
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42 (10A) (trailer tow LH stop/turn)
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105 (30A) (trailer tow electric brakes)
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106 (30A) (trailer tow battery charging)
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Trailer tow electric brake control module
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Circuity
Relay(s)
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Bulb(s)
NOTE: When diagnosing the trailer tow lamps, begin by verifying that the vehicle lamp systems are all functioning correctly with the trailer
disconnected.
4. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
5. If the concern is not visually evident, verify the symptom and GO to Symptom Chart. See: Symptom Related Diagnostic Procedures
