"Trailer Not Connected" message when trailer IS connected

[KKBB]

UPDATE: Problem Solved. Trailer is equipped an after-market brake controller that's tucked up under the trailer tongue/propane tanks and the trailer plug is plugged into this unit. Coming out of this unit is another plug, the one we've been attempting to use, that plugs into the tow vehicle. We were simply able to bypass the remote unit by unplugging from that unit and plugging the original trailer plug directly into our truck, which allowed the truck to recognize the trailer/trailer brakes. The remote unit was not allowing the truck to recognize the trailer's braking system.

Glad ya got it figured out.

 

[Egglefield]

I once had that issue with a Silverado when by breakaway shorted. It killed a fuse and I had no trailer breaks. I had to replace the breakaway, the fuse and I also needed a break job on the 5th wheel. I suggest you start by checking your fuses.

 

[mgr1001]

I had a very similar problem on my 2016 3500. I kept getting intermittent "Trailer not Connected" warning on the dash. The trailer brakes stopped working whenever this happened. Very disconcerting, especially when coming down from the mountains.

Check all the wire connections on both sides of the trailer electrical plug. Make sure that all the contacts in the (7-pin) trailer plug are making good electrical contact.

This worked for me

 

[Lee Pedrick]

In your trailer brake plug, in each position you'll see two brass posts. if they are too far apart, get a screwdriver behind each one and compress them towards each other. That will give you a tighter contact. Not saying thats the problem, but it will eliminate a potential problem. Just sayin!

 

[mlchilders]

My 2016 Bighorn did the same thing. Check the connection at the bumper. At first glance it looked connected but when I touched it, it was loose. The plug had separated, when I pushed together I felt and heard a click when it connected.

 

[spg993tt]

The trailer brake controller senses the presence of a connected trailer by detecting the inductive load of an electric trailer brake. The trailer brake controller will not provide any braking signal if a trailer is not detected. If you have access to another trailer with electric brakes, that would be a test to see if your trailer brake controller is functioning as well as the 7 pin connector and associated wiring.

Another test you can do to prove out the trailer's brakes really function is to pull the safety brake cable on the trailer and see if the brakes are applied. Be sure the house battery is charged and don't leave the safety brake switch engaged too long since it will build heat in the brakes.

When I got my 2015, I had issues with my trailer brake controller. Taking it to a dealer was absolutely fruitless, they simply did not have the resources or the knowledge to troubleshoot. In my case, the issues were eventually fixed through a software update of the controller and ABS module.

I have a tester, it is well made and works well to identify issues. It is a little pricy simply because it can only be used to test the 7 pin but can also be worth its weight in gold. It may be your best option.

https://smile.amazon.com/gp/product/B073FJ5NVL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

great info, thank you. im having the problem of getting a "trailer not connected' on my 2022 ram 2500. there is power on all the pins in the connector and if i push on the break full, i get 11.4volts on the brake power pin.
so if im getting powre as such on that pin, but not breaking power, would it be safe to suggest its on the trailer side?? you mentioned "The trailer brake controller senses the presence of a connected trailer by detecting the inductive load of an electric trailer brake. The trailer brake controller will not provide any braking signal if a trailer is not detected" but if im getting 12v juice on thta pin, is that "providing braking signal"?

 

[BossHogg]

great info, thank you. im having the problem of getting a "trailer not connected' on my 2022 ram 2500. there is power on all the pins in the connector and if i push on the break full, i get 11.4volts on the brake power pin.
so if im getting powre as such on that pin, but not breaking power, would it be safe to suggest its on the trailer side?? you mentioned "The trailer brake controller senses the presence of a connected trailer by detecting the inductive load of an electric trailer brake. The trailer brake controller will not provide any braking signal if a trailer is not detected" but if im getting 12v juice on thta pin, is that "providing braking signal"?

First, be careful, don't let the amount of voltage measured on the trailer brake wire fool you. The brake is not a variable 12-volt signal but a pulse width modulated signal. PWM is a method used to control the amount of power going to the brakes and allows for computer control of the signal. Depending on the volt meter and its sampling rate with respect to the PWM frequency you could get fooled, much like the frame rate of a camera versus the flickering of a vehicle's LED lighting when viewing video.

When running the brake controller manually using the slider, the module will provide an output signal albeit not at or near 100%. When there is a "no trailer-connected" state, no autonomous signal is provided while traveling.

An issue like this, in my experience, is rarely an issue with the tow vehicle. It is always the trailer, its wiring or its 7-way plug not making the best contact. Measuring the presents of voltage is not the same as having current flow and current flow is hampered by poor connections.

Start at the beginning, start with a visual look at the connectors. If it is a new trailer I ask if the brakes have been bedded, seems RV dealers never mention that to a new-be. Then I check the trailer lighting and brake lights. If that is working then a good connection is assumed. Pulling the safety brake-away pin on the trailer should introduce resistance to the wheel rolling (disconnect the 7-way first). The typical trailer wheel brake should pull around 3 amps at 12 volts.

It isn't easy troubleshooting an issue like this because it is difficult to get access to the trailer's wiring but if you can, while it is connected to the tow vehicle, see if you have voltage on the brake line at the wheel. This will answer all but one question.

 

[zrock]

Are you sure your on the trailer brake pin? I would start by checking every fuse since their is 1 fuse for sure that is a shared fuse with the trailer brakes and on a air suspension truck it is not labeled as such. I have a air deleted truck and everything worked except for the brakes, after spending a few weeks on and off checking everything and not finding a thing i was sitting in the truck and realized that i could hear the brake controller activating every time i stepped on the brake and remembered seeing a post somewhere about a fuse and air suspension. Started replacing the fuses 1x1 and found a fuse was the culprit and was not labeled anything even close to brakes or even make you think it was for the brakes