I am having similar issues with my 2011 F150 that I got used about 6 months ago and now when I hook up my camper I get the trailer disconnected message but I had running lights and brake lights when the trailer was connected, however, the factory brake controller does not work at all so I have no trailer brakes. I took out my electrical tester to the connection at the hitch and found that I have power to the turn/brake light pins when activated and the running lights pin when activated but I do not have power to the trailer brake pin - so I brought my electrical tester to the fuse box under the dash and the fuse is not blown but I do not have power at the fuse box when the brakes are activated - so, I went to the fuse box under the hood with my tester and I do have power there. I am wondering 1st if a bad ground at the rear of the truck by the hitch would cause no power at the fuse box under the dash? and, if not a ground issue, what could be the problem between under the hood and under the dash??

Cory

 

I get that trailer disconnected warning message on certain trailers I pull with my 2010. My lights and brakes work so I really don't pay attention to the warning. It is a distraction but I look in my mirrors and see the trailer is still there so I keep on going.

 

How do you know the trailer brakes are working?

Steve

 

No, a bad ground may cause trailer brakes not to work, but it will not disrupt power to the fuses. Have the trailer brakes ever worked now or in the past?

Steve

 

I'll have to trace my trailer wires as well. I get the message when I drive over rough road or take a turn(intermittently of course). I have already ruled out the 7 pin connector as I took it apart inspected both the truck and trailer sides. Dressed everything up and I still intermittently get the message. So time to wring out the trailer...thats almost new.

 

For ****s and grins, have you tried replacing the trailer connector on the pickup? I've had similar issues and it was the pickup connector

 

I am with Chris on this. Mine was not working correctly and it just
turned out that the truck side plug was corroded the harness connector
was still good. Put a new one in and I was back in business.

 

Mine even looked fine, I also tried bending the contacts a bit. Only replacing it solved the problem.

 

Given the description, it sure sounds like the connection at the seven pin, so I vote yes to the above.

Steve

 

Mine has the green fuzz on the pins. Even cleaning it did not help.

 

since it is a new truck to me this is the first time I've had it hooked up to a trailer with electronic brakes and I got it from a dealership that is not being much help and definitely not giving me any history on the truck - I guess they will help but charge by the hour even when they don't fix the issue - last time I brought it in it was over $130 and they told me the fuse was bad - well, now all fuses are good but the issue is still there. That is the last time I'm dealing with them.

 

Crawl under the truck and look at the back side of the 7 pin.
You will see that the harness side has it's own plug. Remove
that plug and have a look at all of the pins on both sides.
Green fuzz is bad.

 

We just bought a new 2017 Ford F-350 DRW truck connected to our 2012 Mobile Suites trailer and I got the "trailer disconnected", "right blinker bulb check", left blinker bulb check" and the blinker blink speed doubled to fast blink. We pulled this with a 2011 Ford and never had connection issues. I replaced the 7 connector trailer wire and made sure each connection was solid, then taped each connector at the junction box of the trailer. I may try tapping into the ground wire and connecting that to the trailer frame. Another thing I did different was I installed a new fifth wheel hitch and used the plastic lube plates instead of using grease on the new hitch plate. I'm thinking since I'm getting all kinds of connection error messages, it must be a grounding issue. Thing is all works well on the trailer including lights, brakes, etc. during the disconnected trailer periods. Any ideas?

 

Lube plate is irrelevant. Your truck and trailer do not depend on the hitch for a ground.

The "trailer disconnect comes from the connection between the truck and trailer and is almost always at the seven pin on the truck. Your messages suggest open or nearly open circuits, and your blinker double timing happens when a burned out bulb opens a filament circuit. My suggestion is to go with a connection issue as the first consideration. I would rule out the common stuff first. Takes about 5 minutes to run a truck frame to trailer ground.

If that doesn't do it, can you hook to another trailer and see if it is the same?

Steve

 

When you say run a truck frame to trailer ground, you mean connecting frame to frame between the truck and trailer with jumper cable or something similar. I know my bulbs are fine all the way around, nothing burned out.