Ford F-350 trailer wiring fault

[checkmate99]

Had a similar problem with my former 2015 Chevy 2500, and 2014 Heritage Glen TT. I would get a "check trailer wiring" message in the DIC, and I would lose my trailer brakes each time this message came up. (It also was an intermittent problem). Everything else on the trailer would work, except the brakes. Had the problem checked at Goshen last year, and it turns out the wiring for the brakes were never grounded properly in the junction box on the trailer frame. At least that's what I was told. Anyway, after they fixed that grounding problem, I never got the message again. Good luck with that problem... electrical problems can be very frustrating.

[Ajrzr13]

Had similar issue on my rig. Also had intermittent brakes. Took it top shop and the found the wires to the magnet had came loose and were rubbing and shorting out.

Good luck

[dbledan]

Originally Posted by DouglasReid

One last item to check..............

I had the same sort of problem, it would come on and off as I drove, with an annoying beep or squeal sound every time. It turned out to be the connection between the trailer plug and the receptacle.

It turned out the cable on the camper was bad and changing it out solved the problem. It could just as easily have been the receptacle or dirt in the receptacle so do your self a favor and check both of these areas as well.

X2 here. I had an issue with mine popping up on a trailer that had no breaks. I ended up having to mess with the trailer connection. I squeezed one side and cleaned the other but it came down to the trailer having dirt on the connector I think. Once I cleaned that out it stopped happening. Not sure if that or messing with the connections resolved the problem.

[Skyliner]

I rewired my last camper's brake wiring and installed new brakes on all 4 wheels.

Lots of OEM frame builders run brake wiring thru the axle. There is a rubber grommet in the axle hole to prevent the wire from rubbing thru against the metal hole opening. This grommet often rots awayf from exposure and brake wiring often shorts against the metal.

Once also had a worn wire insulation in brake assembly causing intermittent short.

Rewire and brake replacement fixed my issues and was an easy 1/2 day job. I installed thicker wire, and soldered connections (factory crimped/wire nut connections showed oxidation in wire)

[DKRITTER]

The time or 2 I've had this happen it was due to a poor connection so I make sure it is plugged all the way in.

[mike and shari]

Had this problem with my previous 5th wheel. Brake wires running through the axle had rubbed and were intermittently grounding out. Ran new wires along the outside of the axles and never had another problem.

[Nguyenbio]

I will be going through the entire system this weekend and will give everyone an update as to what I find.

Thanks again to everyone who has provided input and/or advice!

[Nguyenbio]

UPDATE!!

Before pulling off my hubs, I decided to go through and inspect every brake wire inch by inch. Wouldn't you know it, there was a tiny nick on one of the wires located on the middle axle that was rubbing on the top of the spring mount. The nick exposed enough wire to catch the corner of the mount, which then sporadically sent the wiring fault message due to being grounded out. I repaired that wire and went ahead and checked the inner axle wires. Wouldn't you know it, the third axle also had some bare wire that was exposed in the axle. Apparently, the insulation had worn off bouncing inside the axle. I went ahead and pulled all axle wires, split loomed them, and mounted them on the upper rear part of each axle with large zip ties. This was advice given by members on here and by Dexter themselves. I also split loomed and secured all other brake wires, eliminating any chance of having this specific problem occur again.

I want to say thank you to everyone on here for their advice and encouragement!

[jgump]

Originally Posted by jgump

I have a 2016 F350 and I get intermittent warnings saying left rear turn signal inop. It works but fast flashes. Then it'll go away and flash normally. Then it'll come back and so on. Not sure if it's a ground issue or if I need to clean the 7-way to ensure good metal contact.

Update: I installed a lighted Ford hitch emblem and it's plugged into the 4 way. Truck thinks it's a trailer and I still get the intermittent turn signal fault. Has to be something in the truck now that I get same thing without my trailer. Any ideas?

[Rich5117]

Don't count out the seven way, there have been problems wth the rear wiring getting wet and other junk getting in side the connector, if it is shorting or corroded it could still cause you problems. The other place to check is the plugin connector under the truck where the trailer wiring connects to the truck wiring.

[jgump]

Originally Posted by Rich5117

Don't count out the seven way, there have been problems wth the rear wiring getting wet and other junk getting in side the connector, if it is shorting or corroded it could still cause you problems. The other place to check is the plugin connector under the truck where the trailer wiring connects to the truck wiring.

Thanks Rich. Once it thaws a bit I'll have a look.

[Boatdude62]

2017 F350 DRW 6.7 have problem get 12 volt power to 7 pin truck plug receptacle. Can’t figure why there’s no 12 volt power at either bed or bumper receptacle. Neighbor has 2017 F250 gas motor that has power there. Anyone experience this?

[Rich5117]

Truck has to sense trailer connected for power. Also check fuse number 27 under the hood it is a 30 amp, trailer charge relay. Connected my air bag controller there and it kept thinking they were a trailer when it needed power.