F 350 4WD Super Duty V8-6.0L DSL Turbo VIN P (2004)
Fuse: Customer Interest
Electrical - Diagnostic Procedure For Trailer Tow Lights
TSB 09-7-10
04/20/09
DIAGNOSTIC PROCEDURE FOR TRAILER TOW
LIGHTS - SERVICE TIP
FORD:
2003-2006 F-Super Duty
This article supersedes TSB 06-6-1 to update the Service Procedures.
ISSUE
Some 2003-2006 F-Super Duty vehicles used for towing may exhibit trailer lamps being inoperative or not working properly. This may be due to an
open trailer tow fuse, a concern in the vehicle's wiring, a concern in the trailer's wiring, or the trailer not being wired properly for the vehicle.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
If the vehicle exhibits an open trailer tow fuse, refer to the following to determine if the open trailer tow fuse concern is caused by the vehicle or the
trailer wiring. If the vehicle does not exhibit an open trailer tow fuse, follow normal diagnostics.
NOTE
FAULTS OR REPAIRS CAUSED BY TRAILER WIRING ARE NOT WARRANTABLE.
NOTE
VEHICLE WIRING MAY DIFFER FROM MODEL-TO-MODEL OR YEAR-TO-YEAR. ENSURE THE TRAILER IS WIRED CORRECTLY
FOR THE VEHICLE.
NOTE
ELECTRIC POWER TO EACH TRAILER CIRCUIT IS SUPPLIED THROUGH A RELAY AND DEDICATED FUSE. (FIGURE 1)
4-PIN CONNECTOR 2003-2004 VEHICLES
1.
Check Fuses F2.6 and F2.38 in the central junction fuse box, located under the dash panel, left hand side.
a.
If the fuses are okay, do not continue with this procedure. Follow normal diagnostics to determine if the issue is in the vehicle or in the
trailer wiring.
b.
If a fuse is found open, proceed to Step 2.