Trailer Wiring Fault Message on 2017 Ford F-350
Question:
I have a 2017 F-350 and i get a Trailer Wiring Fault when towing my 5th wheel. You can not predict it other than it will happen and usually when pressing the brake pedal or in dash brake controller. Sometimes its right away and sometimes its after many miles. My understanding is its saying an issue in the brakes on the trailer side. I have read it could be many things but before I tear into and buy random parts, was wondering if yall had a procedure or checklist to walk thru?
asked by: Andy
Expert Reply:
I took a look at the owner's manual for a 2017 Ford F-350 for you and found the following under "Wiring Fault on Trailer"
"Displays when there is a short circuit on the electric brake output wire. If this message displays, with no trailer connected, the problem is with your vehicle wiring or trailer brake controller. Contact an authorized dealer. If the message only displays with a trailer connected, the problem is with the trailer wiring. Consult your trailer dealer for assistance. This can be a short to ground (such as a chaffed wire), short to voltage (such as a pulled pin on trailer emergency breakaway battery) or the trailer brakes may be drawing too much current."
If the issue is with the trailer connected, I would first recommend checking the trailer connectors for corrosion. If there is no corrosion then you'd need to begin checking and tracing wires on the trailer, starting at the tongue and working your back to the lights/braking assemblies.

Product Page this Question was Asked From
Tekonsha BRAKE-EVN Trailer Brake Controller - 1 to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Plug-In
- Under-Dash Box
- Under-Dash
- Up to 4 Axles
- LED Display
- Single Trailer Only
- Tekonsha
more information >
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