I own a 2018 F-150 with the maximum tow package option. On our trip up to northern Minnesota, I was towing my friend's 2022 trailer / boat and kept on receiving the warning message "Trailer Disconnected". Trailer was properly connected to my truck and had all lights working. We were also able to adjust the trailer brakes. We stopped by a Ford dealership on the drive up and the service technician suggested we clean the terminals of the trailer plug as perhaps dirt was causing the problem. Well we did buy some electric contact cleaner, and this did not solve the problem.
Any suggestions from those who have experienced this problem?
Thanks in advance for your help.

 

Contact cleaner removes some types of grease, and some Carbon. It does not remove corrosion or dirt. Post pics of the terminals in the truck's socket, and on the trailer connector.

 

Shoulda disconnected and plugged back in the wiring harness to the plug on the bumper. Reseat the connections.

new doesn’t mean good.

 

Thank you for your response but be advised that we did clean the contacts while on the road and this did not solve the problem.

 

Were you driving in a wet / raining conditions?

 

Yes - but the problem started while driving in dry weather.

 

not the pigtail to the trailer.


the one underneath and on the backside of the bumper.

there’s a connection there and it’s not unheard of for that actual plug to be bad and need replacement

 

Got it!

 

There is a plug at the back of the 7-pin behind the bumper, then another a little bit down the wiring harness. Disconnect and clean both, check for corrosion, and remove it if required. Then fill with dielectric grease and re-connect.

There is also the ground back there. Do the same with it.

 

I was towing my utility trailer awhile back and I started getting the disconnected message. After inspecting the trailer harness I found that someone I had loaned the trailer to had dragged the harness and nearly severed a wire. I spliced it an that was that. I would check the harness of what's being towed very thoroughly.