Wiring fault brakes don't work.

[shvanhorn]

I have a Jayco Eagle 338 RETS, pulled with an F-250. I get a wiring fault and the brakes don't work, after I test them manually from the cab. Is this an easily fixed issue. I don't see any wires broken.

[Sscheitel]

I am getting the same error on my F250 same thing....no brakes. Did you ever determine the issue?

[skids]

The first thing I would do is a thorough cleaning of the connection between the trailer and truck and then recheck.

[shvanhorn]

I tried the cleaning and that didn't work. I took the truck to the dealer and they found a wire rubbing and fixed that, but I still have the problem. I'm taking the truck and trailer to the trailer dealer, this weekend, to see if they can isolate it to the truck or trailer. They supposedly have a tool they can hook up and tell. We'll see and I'll do another post afterward.

[curver900]

https://www.matcotools.com/catalog/p...RAILER-TESTER/

maybe cheaper may not at least you know which side is broke and not working.. most likely a ground...

here is a cheaper one.

https://www.ipatools.com/products/ipa-7865l.html

[cfisher523]

In my experience truck to trailer issues usually boil down to ground issue.... it looks like you had a short (argueably a ground issue too ).

Anyway, since you are still having a problem, I had a similar issue with a 2010 Silverado. Brake controller seemed to be working fine, all wiring seemed to be good, lights worked as wired/intended, but no power to the brakes and an error message on the Drivers Information Center (DIC).

Turned out I had a bad JCase Fuse (30amp) that supplied the power for the brakes. Replaced the fuse, error message went away, and all started working again. Not sure how Ford supplies power or determins error messages, this might not help at all, but it's something I worked through and I hope it helps in some way. Best of luck!

[dmward]

I had this with my F150 last summer, towing thru hilly Northern Ontario (yikes). I cleaned the connections thoroughly with a screwdriver and WD40 until they were shiny, but the probably still popped up.

It turned out to be an exposed brake wire on where the cable exits the trailer. Some electrical tape fixed that issue.

[RVhiker]

Here's another possibility causing a short. On Dexter axles, the power feeding the brake magnets gets from one side to the other via a wire inside the axle, running from one side to the other. This two conductor wire can abrade on the rough interior of the axle, and cause a short. Happened to my trailer.

[oldmanAZ]

Probably doesn't apply to the OP, but...

On a few occasions, my brake controller indicated a brake fault while going down the road and I had no TT brakes. Everything seemed fine as far as I could determine. Unplugging and replugging the trailer connector cleared the fault... until the next time.

I tried using a short bungee cord to keep the plug TIGHT in the socket just as a 'test'. The problem did not reoccur. After many years, I'm still using that short bungee.

[redenbacher]

I own a 2015 GMC Sierra 1500 with an integrated trailer brake controller and a 2015 Jayco 27 DSRL. My issues started last September on a trip to SD/WY. It would display "check trailer wiring" on my dash display and would have a loos of brakes and then trailer brakes would restore. It would go back and forth with no brakes, then brakes and then again no brakes. Sometimes, it would resume right away and other times brakes would be non-functional for quite a while. Trust me, driving through the hills in WY were NO FUN! I had the trailer and truck looked at in Custer, SD before heading into Wyoming. They could find no issues. The truck was taken back to the dealer when we returned to IN and they could find nothing wrong. I took the trailer to an independent shop and they said they checked all brake connections and no issues there either. After having issues all though last autumn and spring we've had the truck back to the dealer no less than six times. Now we are going back to the trailer repair facility this week. You folks have given me some ideas to discuss with them. I'll report back. BTW, the GMC dealer did replace both sides (truck and trailer) of the 7-pin connector but the issue is still there.
Dan

[shvanhorn]

Took the trailer in and it was the trailer. There is a magnet in the brake for each wheel and something related to that went bad. When they checked it at the dealer, the brakes were pulling more amps, then expected and the wheels weren't stopping at the same rate. They replaced part related to the magnet and the problem is supposedly fixed. We pick the trailer up this weekend.

[ARMYG]

I noticed my brake wire connections were all corroded while repacking my wheel bearings. The connections are made with a crimp around several wires and a supposedly water tight jacket installed. My rig is only two years old and these connections don't give me the warm fuzzies in regard to braking. I will cut back each connection, solder them and apply liquid electrical tape with two coats. Finally, I will install two layers of shrink wrap

[Sscheitel]

Mine wound up being the a short within the brake assembly. Those two sets of wires that are exposed behind the wheel(s). Replaced a set of those wires and no more faulty error on my truck.

[ARMYG]

I also notices several sharp edges that the two electric brake wires contact, one is at the axle tube hole that sends the wires to the passenger side of the rv.

[redenbacher]

As an update to my problem, I had been going back and forth to the GMC dealer for about 2 months. The service tech, working with the engineers in Detroit, created a device that mimics a connected trailer. It sits in the truck bed and uses the same brake magnets as those on the trailer. Alas, we finally determined the issue is not the truck. Now back to the trailer service facility.

[Atlee]

I had a brake fault register on my truck with my last trailer. The reason was a broken wire to one of the brakes. The RV repair shop rewired all four brakes.

[oldmanAZ]

Originally Posted by redenbacher

As an update to my problem, I had been going back and forth to the GMC dealer for about 2 months. The service tech, working with the engineers in Detroit, created a device that mimics a connected trailer. It sits in the truck bed and uses the same brake magnets as those on the trailer. Alas, we finally determined the issue is not the truck. Now back to the trailer service facility.

It's a good news , bad news sort of thing .

Kudos to your GMC dealer and the engineers in Detroit for going to that level to resolve your problem.

[24travel]

Don't know if this will help the OP or anybody else. But I have a 2017 Chevy Colorado Diesel with integrated brake controller. I started getting "check trailer wiring" and was losing my trailer brakes, all the lights and turn signals were still working, just not the brakes. Through another forum, I found that the trailer brakes and the Cruise Control run on the same relay/fuse. So when I turned off the Cruise control in my truck, I have not had any problems since. This is going on 10 months. So I don't get to set cruise, but I always have my trailer brakes.

[dornoski]

My f250 constantly indicated trailer disconnected. Ended up rewiring entire electric brake system on TT. In the process I found that 3 out 4 brakes never worked right from factory. They were rusted in place from non use. I replaced all brake wire including the thin thermostat type wire Jayco/Dexter used that runs through the axle, it was shredded from pulling the wire through the little holes in the shaft. All connections i used were crimped/glued heat shrink connectors. I believe I used number 10 brake wire. Also replaced the standard interior home electrical box (non-waterproof) that was install at factory on trailer frame. Again all heat shrink crimped connectors and a new terminal box from etrailer.com all new ground wires too. Brakes work great now and it doesn’t indicate trailer disconnected. The main cause was that thin wire within the axle was bouncing around shorting out.