I posted this about 6 months ago, but didn't want to resurrect an old thread. My truck is a 2014 Silverado with factory ITBC brake controller built in. While towing, I randomly get the "Check trailer wiring" message on the dash and then a second later, it says "Trailer connected". During that split second, I indeed have no trailer brakes. Several months ago, I replaced the plug on the trailer end with the Pollack brand plug as that is what some here recommended. I was hoping that would fix the problem, but it did not. This weekend was my first time towing any distance since doing this and while towing it home today on a 4 hour drive it was doing this constantly, for 4 hours. Obviously, this was making me very nervous. Wiggling the plug and plugging it in better did not help the problem. I crawled under the trailer and found the end of the main trailer plug where it goes into a metal junction box. I opened the juction box and had my son sit in the truck with it running while I wiggled these wires in the junction box, and nothing happened. The only way I could recreate the message was to unplug the camper and then plug it back in. What should I check next? Could a short between this junction box and the actual brakes be causing this problem? Could it be a problem with the truck or the truck end of the plug? I'm hoping someone here can help. Thanks.

I'm thinking after reading your testing info so far that it's on the truck end of the plug.

Many trucks have an adapter on the truck. The chassis wiring has a large connectorthat the blade assembly connects to.Note the connector and then package with replacement truck wiring pigtail and connector.Pollak replacement

An intermittent open circuit is possible. Check the wires all the way to the brakes themselves, including any grounds.Ideally you’d have another trailer to try pulling or have someone else pull your trailer to determine if it’s a truck or a trailer issue.

Junk wiring on the trailer.Typical spot for intermittent wiring faults is the wires that run INSIDE the axle tubes. Those wires are loose inside the tube which leads to chaffed insulation which leads to intermittent shorts in the wiring.The moving wires also can eventually break leading to loss of brakes..Best bet is to scrap the existing brake wiring on the trailer and run NEW wire and wire tie the wires to the OUTSIDE of the axle tubes.Replacing the wire is the easiest and fastest way to fix intermittent issues.You can also use that as a upgrade route, move up a couple of wire gauge sizes and pickup better braking..

Gdetrailer wrote:Junk wiring on the trailer.Typical spot for intermittent wiring faults is the wires that run INSIDE the axle tubes. Those wires are loose inside the tube which leads to chaffed insulation which leads to intermittent shorts in the wiring.The moving wires also can eventually break leading to loss of brakes..Best bet is to scrap the existing brake wiring on the trailer and run NEW wire and wire tie the wires to the OUTSIDE of the axle tubes.Replacing the wire is the easiest and fastest way to fix intermittent issues.You can also use that as a upgrade route, move up a couple of wire gauge sizes and pickup better braking..X2100% of the intermittent issues I saw it was exactly that- wires in the axles that had insulation worn thru.

Still getting "Check trailer wiring" message 2014 Silverado

IPegasus
Explorer
Apr 11, 2019
Gdetrailer wrote:
Junk wiring on the trailer.

Typical spot for intermittent wiring faults is the wires that run INSIDE the axle tubes. Those wires are loose inside the tube which leads to chaffed insulation which leads to intermittent shorts in the wiring.

The moving wires also can eventually break leading to loss of brakes..

Best bet is to scrap the existing brake wiring on the trailer and run NEW wire and wire tie the wires to the OUTSIDE of the axle tubes.

Replacing the wire is the easiest and fastest way to fix intermittent issues.

You can also use that as a upgrade route, move up a couple of wire gauge sizes and pickup better braking..

This is what I found to be the answer to the "check trailer wiring" message. I chased all the other options for a long time. The wires inside my axle tubes had the insulation worn through. I put new wires on the outside of the axle tube. Problem solved.
campinia
Explorer
Apr 02, 2019
Good luck with this. I did many of things that you have done including replacing the plug from the trailer with the recommended one, took the new trailer to the dealer twice, took the new Chevy truck to the dealer twice, and after all that, I still received the message. I sold the truck and bought a Ford, it doesn't do it anymore!
DustyR
Explorer
Apr 02, 2019
enblethen wrote:
I would make splices with crimp butt connectors filled with electrical grease and covered with heat shrink.

X-2

The quote above or soldered and use heat shrink tubing to seal. The scotch guard connectors often fail due to being unsealed. Galvanic corrosion is usually the cause.

I usually spray the TT & TV vehicle power plug/receptacle with WD-40 at the beginning of the season. Occasionally you may need to compress the contacts on the TT plug as they will spread and loose the ability to make a good tight electrical connection.
enblethen
Nomad
Apr 02, 2019
I would make splices with crimp butt connectors filled with electrical grease and covered with heat shrink.
wnjj
Explorer II
Apr 02, 2019
enblethen wrote:
Those are filled crimp scotch locks. They pierce the insulation. Do not make the best connection on some wire especially the wire coming from the magnets.

A flatbed trailer I bought came with "normal" scotch locks. After connecting up one day to find I no brakes, I traced it to those worthless things. I removed them all in favor of twisting and soldering the wires together. My brake controller showed more LED's of braking strength then it ever had before with that trailer.

When I added brakes to my little cargo trailer, it came with the heavier gauge paired brake wire. Only then did I realize all of the LED's could light up, even with only single axle trailer. I never had more than half, even with the fixed flatbed wiring.

If you want brakes, run quality wire and use quality connections.
enblethen
Nomad
Apr 02, 2019
Those are filled crimp scotch locks. They pierce the insulation. Do not make the best connection on some wire especially the wire coming from the magnets.
plasticmaster
Explorer
Apr 02, 2019

Here's the pic.
Tin-bender
Explorer
Apr 02, 2019
Had the same problem on my 2014 GMC, Flushed, filed, and cleaned the connectors inside the truck plug, problem solved.
Tinbender
plasticmaster
Explorer
Apr 02, 2019
I'm having trouble posting pic.
plasticmaster
Explorer
Apr 02, 2019
Okay, I think I found the problem. Without the trailer attached to the ball hitch, I plugged the trailer cord into the truck. I was able to wiggle the wires and weird connectors just outside the trailer hub and recreated the problem. It must be a bad connection inside these weird connectors. Therefore, I'm going to replace all of these connectors. I'll try to post a pic of the weird connectors in a moment. What type of connection should I use?