Short in seven plug ground connection

[Jim McCormick]

We tow our 2015 Rockwood Signature Ultralite with a Silverado 2500 HD. On our first outing, a screen saying " check trailer wiring" displayed on the dashboard, even though all lights and brake controller functioned normally. We left for the campgrounds. When backing into our site, the left front brake locked up, making backing onto my new Anderson levelers impossible. A local car/tire shop found a shorted out ground wire in the seven plug.

My question is: do I only have to replace the trailer plug in or the receptacle in the truck as well? And is the locked brake connected to this or a separate issue all together. Oh yeah, I neglected to say that the short killed my deep cycle battery! Trying to get all issues resolved before out next trip in two weeks. Thanks for any help. Jim

[Asrabbit]

In my thinking a problem at the 7 pin connection should not have impacted just one brake. A short will absolutely get you a warning message. Now, if the issue had been in just that one brake, you would have gotten the message.

Also, I guess I would want to know what shape the brakes are in on the wheel that was locked up. Did that happen only as you were backing in, or was it going on while you were driving? If only while backing in, then likely no real harm.

To me, the only way you would get one locked up would be something mechanical or you somehow had full power to that one brake but not the others, (which would seem to indicate another problem). So, I guess I would want to determine why that one brake locked up but not the others. If all of them had locked up, then I could see how it might be related to the problem in the 7 pin plug.

I don't guess all of that was much help other than to say you may just need to look at each problem individually and you may find they were either related or not related as you troubleshoot the issues.

[AquaMan]

Usually when 1 brake locks up it's because all the power is going to that brake and the issue lies in the brake that didn't lock up. The brake wire is one wire and the brakes work or they don't. Since 1 brake is working I say the problem lies in the wiring at the axle to the other side. I would check voltage at the brake that didn't work. The shorted ground may be a separate issue.

[jk510]

I'm confused as to what a shorted ground is. Normally a wire with voltage is shorted to ground. A ground wire shorted to ground would be nothing.
It sounds to me that there is a problem in the trailer wiring. I believe that the power to energize the brakes comes from the controller in the TV so the trailer battery isn't used at all. It sounds like there is a short between the battery hot wire and the locked up brake. No idea why they aren't all locked.

[5picker]

Jim, I hate to tell you but you've got other problems or the repair shop didn't correctly convey what they found. Dead batteries and one brake locking up are signs of something else going on.

As mentioned, a 'shorted ground' really isn't even plausible. The ground wire could have shorted to a power wire but it still wouldn't be called a 'shorted ground.' By design, the ground in a DC electrical circuit is what other things 'short out' to.

I guess my first question is... do things work normally now that it was repaired?

And why are you replacing the 7 pin plug (or thinking of the receptacle) if it was repaired?

[llr]

Many people call an open a short which would make a little more since. Ground shorting to any other wire should have blown a fuse.
An open ground could cause the warning light and battery not to charge. Brakes sound like a separate issue. Unless the issue was the charging wire shorting to the brake wire.

[DouglasReid]

I see two possible problem areas.

First, all four brakes operate on a single wire supplying power to each. If only one is locking up then the area to look at is the wiring between the brake that is working and the rest. You could have a broken wire preventing all the rest of the wheels from getting power to them.

Second, would be your Emergency Brake system on your camper. It supplies power from your camper battery to all the brakes in the event the camper become detached from your TV. If there is a problem there it could cause your brakes to be energized all the time, subsequently draining the battery. If this is the case that one wheel will be dragging and getting VERY hot. (NOT GOOD!) I would insure I had the problem solved before I pulled the camper again. If this is the case issue Id have the brakes on that dragging wheel and the grease on that wheel checked too, to insure the overheating did not cause a problem with your wheel bearings!

Good Luck, please let us know what the trouble is once you find out.

[Jim McCormick]

My thanks to all of you for your help. I need to clarify a few things. I wasn't braking when the left front wheel locked up- just backing up. And the plug is burned/melted in the area of the ground wire. Nothing was hot in the brake/ wheel areas. I have an app't Mon. to,have all the wiring checked. Will let you know how it all shakes out. Jim

[Rivnut]

Jim;
I just went thru this problem. The messages came up same as yours. Went to two different shops, no help,
GMC dealer computer says trailer wiring is problem. Finally I tied back the blue wire in the seven pin plug. drove around in local area and no messages. Took it to another repair shop, told them what to do, "look at the brakes". They called a day later and said the brakes are worn and left front brake has wire loose shorting to ground inside the brake housing. I don't have equip to jack a torsion axle trailer or I would have. Also get the 7 pin plug from E-trailer designed for GMC-Chevy.
good luck
Charlie