I have a 17 F250 Super duty while towing today I got a message that said the trailer was disconnected and went out but then it happened again called Ford dealer and said we never heard that before .any help would be appreciated. I think it's the connector

 

This problem actually happened with my '17 350 as well. Turned out it was the brake controller that had to be replaced. Prior to taking it to the dealer check and make sure you don't have any dust or dirt covering the connector. I found this was really bad on my F-150.

 

It used to come up often on my 2013 F150 until I replaced the plug on the trailer harness. Not sure which wire it checks to know if a trailer is attached, but a new plug never hurts.

 

Mine occasionally does this as well. Seems it does it more when pulling a trailer without brakes. Hasn't happened enough to concern me a lot, but I probably should have it checked out.

 

your wire from the trailer isn't to short is it?
Hooking my trailer to my new truck , all my wiring and chains are to short to reach with play, so when I take a right hand turn it pulls on the connector and I get the trailer disconnected warning.

Rob

 

It has happened once with my 2017 F350. I knew what it was because it happened a lot with previous Silverado. For me it has always been the connection between trailer and truck. I give it a good hard shake when plugging in and that really helps. The F350 is definitely a tighter connection than the Silverado was but it did still happen once with F350. Then again it might be a bad connection elsewhere with yours.

 

Bad grounds, loose contacts in the connector, plug not being fully connected on the back of the truck side connector.. it's not a hard message to get.. Used to borrow a trailer and had it go off about every 1/4 mile.. I finally decided since I was using the trailer more than the owner, I should fix it. Ended up just rewiring the entire trailer.. grounds were shot everywhere.

 

With most 7 pin connectors you should push the trailer's cable firmly into the truck's plug and then press the the 7 pin connector cap down so that it locks the trailer cable into the plug. That's how I know I got the cable all the way into the plug.

Otherwise, I get no trailer disconnect message when the trailer is actually connected.

 

My truck is fine when hooked to the trailer but when I press the slider on the brake control it says it's disconnected, although my plug is clean and tight and the lights are all on, I am about to go test the voltage output on the truck plug to insure it is working. Is there anything else I can try to get this fixed, my trailer works fine on a 2011 F-150 with an aftermarket brake controller, and it worked fine on my last 2 F-150's with the factory controllers in them too? I'd like to solve this!!

 

Are you getting any braking action at the trailer? I doubt you would if it says that it's disconnected. Maybe a fuse or relay is missing?

 

Sounds like you don't have a ground for the brakes.

 

Just asking, if I hook this trailer to an F-150 with a regular brake controller, it seems to work but maybe a bit weak? Would each wheel have an individual ground to check? Thanks for the help!

 

The brake circuit for each wheel should ground at the actuator. The ground then has to loop back to the truck, typically through the hitch.

I have seen hitches with vibration isolators that didn't provide the ground so a separate ground circuit through the connector is necessary. Such setups have a ground wire from the trailer chassis through the connector to the truck connector and then back to ground on the truck.

Hitch the trailer to the truck and use an Ohm meter to see if there is continuity between the trailer chassis and the truck chassis. If not, then you probably need to add a ground wire to the connector.

 

The hitch should NEVER be acting as your ground. There's a ground wire in your trailer connector that provides ground. On the trailer side it tends to be run to the trailer frame, and then uses the frame as the ground to the rest of the electrical. And that point tends to corrode. I prefer to run a clean ground to each electrical item and avoid using frame ground.

 

What Xwild said. The hitch/receiver/coupler is a very unreliable electrical connection. Ever notice all the lights flicker on a trailer in motion? Likely cause is poor grounding via the hitch.