Montana trailer connection

[Randy E]

Hi everyone.
We have a 2017. 3791RD that we tow with a 2016 Chevy Dually diesel crew cab. Every time I tow, I get an occasional warning on my truck dash that says ‘Check trailer connection’. Then immediately I get ‘Trailer connected’. Each time it dings to get my attention. I can tell you the trailer lights never blink off. The rear camera never goes off the brakes work as well during the warning. I did notice it does it more in a low speed stop and go situation. During a traffic jam it went off 20 times. I’ve tried to find it. I even installed a new trailer 7 pin plug. I pull 2 other trailers and never have an issue.
This Montana has the Mor-ryde pin box that has plastic bushings and rubber shock absorbing blocks inside. Do you think this might be a grounding issue?
During stop and go driving the pinbox slides all over.

Has anyone else ever had this type of issue?
I was thinking of adding a ground jump wire from the truck to the pinbox just to see if that helped.

Thanks for your thoughts
Randy & Tracy
Hermitage Pa.

[Vet4jdc]

I had this happen before and it was water in the 7 pin connector. Not the one to the trailer but where the connector ties to the harness under the truck. Check all your connections. It's acting like mine did from water.

Originally Posted by Randy E

Hi everyone.
We have a 2017. 3791RD that we tow with a 2016 Chevy Dually diesel crew cab. Every time I tow, I get an occasional warning on my truck dash that says ‘Check trailer connection’. Then immediately I get ‘Trailer connected’. Each time it dings to get my attention. I can tell you the trailer lights never blink off. The rear camera never goes off the brakes work as well during the warning. I did notice it does it more in a low speed stop and go situation. During a traffic jam it went off 20 times. I’ve tried to find it. I even installed a new trailer 7 pin plug. I pull 2 other trailers and never have an issue.
This Montana has the Mor-ryde pin box that has plastic bushings and rubber shock absorbing blocks inside. Do you think this might be a grounding issue?
During stop and go driving the pinbox slides all over.

Has anyone else ever had this type of issue?
I was thinking of adding a ground jump wire from the truck to the pinbox just to see if that helped.

Thanks for your thoughts
Randy & Tracy
Hermitage Pa.

[Hunts900]

I have the same issue with the same truck. By the time I find a place to safely pull over it has solved itself. I think it has to do with the 7 pin connector in the truck bed flexing during turns and bumps....but who knows. It is so infrequent it’s more of an annoyance, so I haven’t fully investigated.

[jetskier]

Try using contact cleaner on the 7-way connector and a small wire brush to clean the connections.

[BB_TX]

Does anyone know exactly how the trailer connection sensor works? What is it actually sensing? There would have to be some type closed loop electrical circuit.
I can not find anything on the web that describes it. Lot of opinions, but nothing that I would consider really knowledgeable or official.

[BuilderBob]

If I remember correctly it senses the resistances in the ground circuit.

[RichardD]

I have had this problem with 2 different 5th wheels with my 2015 Chevy Dually Duromax crewcab. I was pretty sure that it was a truck problem but after months of dealer appointments and even a GM Engineering inspection it turned out to be a 5th wheel problem. On the first coach, an SOB, it was inside the brake drums. The clips that hold the magnet wires onto the brake shoes had come off allowing the wires to rub on the drum. Once the insulation had been rubbed off the wires, the bare wires would cause a short that the truck's trailer brake system would send a message to dash. The second 5th wheel was on a 2 month old Montana. A little different problem this time and it was easier to find. A brake shoe retainer came apart causing the brake magnet to be constantly rubbing on the drum. Not only did I get a message on my dash but I got a message in my rear view mirror. My wheel was smoking, I immediately pulled over, no fire but a very hot brake drum.
Both times I was lucky, never lost the brakes or a wheel, thanks to my truck telling me there was something wrong with my trailer brakes.

I hope this helps!

[speedster100]

spray the connectors with WD 40, wire brush the male end as best you can and spray both the female end and male end again. Plug them together and take them apart a few times and you should be good. Every month or so spray them with WD40 again... They get slightly corroded sitting in the open air due to moisture.

[jetskier]

WD-40 Specialist Electrical Contact Cleaner Spray - Electronic & Electrical Equipment Cleaner. 11 oz. (Pack of 1) - 300554-E https://smile.amazon.com/dp/B00AF0OF..._HTjTCbCSAP8VR

The sense is from the electric brake circuit. If you put one of those 7-way LED light circuit checkers in the truck connector, it will flash every few seconds even when the brakes aren't applied. Once it senses the resistance of the magnet or hydraulic controller, it knows it has a trailer plugged in. This doesn't apply to non-brake 4-way type trailers.

ONLINE LED STORE 7-Way Blade Trailer Wiring Tester [Nickel-Plated Copper Terminals] [Continuity Test] [Rugged Material] 7-Pin Trailer Light Wire Circuit Tester https://smile.amazon.com/dp/B07G8R3K..._8ZjTCb1MN7TB9

[BB_TX]

Originally Posted by jetskier

.....
The sense is from the electric brake circuit. If you put one of those 7-way LED light circuit checkers in the truck connector, it will flash every few seconds even when the brakes aren't applied. Once it senses the resistance of the magnet or hydraulic controller, it knows it has a trailer plugged in. This doesn't apply to non-brake 4-way type trailers.
.......

My 2012 F350 does not respond like that. The LED on the 7 way tester for the brake circuit comes on when I press the brake, off when I release the brake, but the dash still shows "Trailer disconnected". No flashing on the tester or the dash. But when I connect to the trailer, it shows trailer connected.

[Briarglenn]

Check your ground.

[twindman]

I had a similar problem but not as bad. When I would start out each day, it would happen 3-4 times in the first couple of miles. I cleaned the inside of the 7 pin and everytime I plug in, I remove it and redo it 2 or 3 times and no longer have the problem.

[TK1]

Had the same problem with our 3400RL pulled buy a Chevy 3500. The solution that worked for me was to spray both the trailer cord and truck plug liberally with electrical contact cleaner and then apply dielectric grease to both, haven't had the problem again !

[Randy E]

Thank you all.
I added a jump wire from my truck directly to the pinbox but it did nothing. So I think my next move is to clean the plug and socket as stated real good. If that doesn’t help I’ll pull the wheels off and check the brake wiring.

I appreciate all the free advise.

Randy & Tracy.

[Todd727]

It’s not going to be the plug. Pull the wheels an check the brake wiring. One of the brake wires is shorting out. I went through everything you are going through. When I pulled the wheels, the wires were routed incorrectly, were chafed, insulation was missing and one wire was broken.

[laverdur]

I have not read all the responses to your question but I had a similar experience with my TV and my Monty. After hours of troubleshooting and not finding anything while parked, I finally bought a spool of wire, some crimp connectors, some liquid tape and some zip ties. I cut the wires that run through the axles and ran new wires on the outside of the axles. Have not had a problem since. When I pulled the original wires out of the axles, the insulation had chaffed through to bare wire in several places. Every time one of those bare places would touch the inside of the axle tub while driving, the truck would go nuts with warnings.

[jgeorger]

Had the same issue, bit with loss of brakes message. The issue was in the trailer brakes.

[Smokey946]

Hello Randy,

I have the same camper with the exact same problem with a Chevy truck. After several long camping trips and two trips to the dealer with no fixing the issue I finally found the problem. The issue your having is inside the brake drum of one of your axles. The ground wire that is clipped on the the electric arm inside the drum has come off the clips and become frayed causing it to ground out periodically which makes your truck think the trailer is disconnected. To find which one it is. Hook your truck up to the camper and then lift one side of the camper up until you can free spin the wheels. Have someone in your truck while you spin the tires so they can tell you when it dings. When. You find the culprit. Call dexter axle they sent me four new brake assemblies to install. That fixed my trailer connection issues. Hope this helps.

[rollingdownthehighway]

I have the same issue in all of my Chevy's even when towing our TT's at first. It happened once with the Monty so far. Never really worried about it. I drive with the lights on, so if it pops up, I check to see if the lights on the Monty are on, which they always are even with this message popping up, if they are keep rolling.

[Chasersr]

Had the exact same problem. Here is what I found after doing all the cleaning of trailer wire connectors and frustrations of chime dinging away. Btw when mine said check trailer wiring I had no brakes. Needless to say all repaired now. Just got back from a 5000 mile journey and not one problem.