Troubleshooting Trailer Wiring on 2013 Ford Expedition

Question:

I have a 2013 Ford Expedition. I have zero power to any of the functions for my trailer lights no turn signals, running lights or brake lights. Ideas?

asked by: Scott L

Expert Reply:

I did not find purchase history for you to confirm which wiring kit you have installed in your 2013 Ford Expedition but if you have recently installed one of the kits intended for your vehicle (shown on the linked page) and you do not have output on the contacts for the trailer there are a few things to check. If your wiring has been on the vehicle and has suddenly stopped working then the likely causes are blown fuses, bad relays or corrosion in the connectors.

First, make sure that your harness's connector is fully seated to the mating one on the Expedition. Some wiring parts like 4-pole # C55384 plug in to the vehicle in between the rear of the trailer connector and the OEM wiring harness that connects to it. If a part like this was installed without the connectors being fully seated together you may have no lighting output signals.

You can also check that all trailer-related fuses and relays are in place. I checked an online copy of the owner's manual (pages 291-293) and the following fuse or relay positions relate to trailer lighting:

24 Trailer tow park lamp
28 Trailer tow park lamp
37 Trailer tow left hand stop/turn relay
38 Trailer tow right hand stop/turn relay
45 25A Trailer tow stop/turn lamps fuse
58 15A Trailer tow backup lamps fuse

If you check these fuses/relays and still have an issue please tell me more about the part you have installed. Please note the part you referenced, # 118242, fits only the Ford F-150 pickup, not your Expedition.

I also suggest you test the trailer light without connecting the trailer to the vehicle. Apply direct 12V battery power to each circuit on the trailer, one at a time, to see if the functions work when directly powered in this way. If so, then you know the problem is on the vehicle.

expert reply by: Adam R

Eric

7/1/2020

I found that I had running lights but no turn or brake on the trailer. Ended up being fuse 24 under hood in main panel. 25 amp small fuse. I found a spare in number 4 spot in interior panel passenger side. Not exact but got me home.