Trailer disconnected / connected error F150 wiring FIXED

I've had a trailer error popping up on my dashboard for the past few months. Most videos talk about the outside trailer connector, which I doubt has solved your problem. I finally decided to fix it for good and work on the real issue - water ingress at the trailer connectors under the vehicle.
Problem solved.
Thie applies to amy vehicle. F150 F250 F350 Ranger/ Sequoia / GMC / Chevy Silverado / etc

[@SevenD7PRIME]

This was incredibly painful to watch. I would have appreciated watching your conclusions and hearing concise solutions, rather than watching each trouble shooting step. The viewers have no idea if your steps to fix the issue will work until the final few seconds of the video.

[@JesseF150]

I have a f150 2018 my trailer lights go off and on all night ,was that happening to you?

[@BartFixesIt]

No, but it is probably related to bad / dirty connections in the harnesses

[@bigfoot761]

When you are greasing a connector you should do the exact opposite of what Bart has done. You want to grease the intercourse of the pin and the socket. As most males know putting the grease around the socket doesn’t work. Get a small wooden dowel cover it with grease and work to get some on all the pins. Now plug and unplug multiple times. Until satisfaction is achieved. (And no I do not see any sexual overtones in my comment )

[@drillsergeant623]

🤣🤣🤣 everything you touch might be the problem.

[@mateocarlos2674]

I had a problem where my trailer would lock the brake wheels whenever the wiring connector was installed between F-150 and trailer. I finally snapped that maybe the +12V was connected where the brake wire was. Sure enough, that was my problem. So I am troubleshooting this issue. From all sources the +12V pin is directly opposite the ground pin. In my case, that reads 0V, but the blue wire has the +12V on it. My pins look like yours. Somewhere in my vehicle, the brake wire and the +12V accessory wire must be crossed????? Any ideas?

[@BartFixesIt]

I would guess it would be either close to your controller or close to the trailer wire, maybe even a trailer wire crossed

[@mateocarlos2674]

@@BartFixesIt Turns out the wiring was correct. The problem was the counterfeit brake controller was putting +12V on the brake line all the time. Tried an actual genuine Ford part, and everything works. Also discovered the accessory power isn't applied until the brain in the vehicle decides an actual trailer is connected. I haven't verified if mine works or not, but the brakes work great now.

[@scottpoore8080]

I have heard dielectric grease conducts and will cause shorting if used liberally. Did you or have you experienced this?

[@scottdelaney98]

I had the same problem and wasted about half a day chasing the problem on my newly wired trailer. Finally I gave up and bought the $11.99 vehicle side tester and discovered the problem was the same as yours; dirty connections at the plug. I cleaned it up and slathered the dielectric grease as you did.
But I have a further problem in that the plug that connects the wire harness to the 7 way trailer plug won't click-lock into place as yours did.

[@BartFixesIt]

There must be something holding it out a little

[@scottdelaney98]

@@BartFixesIt it's getting fully in there, I think the prong is just bent down a little bit so it doesn't snap shut.

[@BartFixesIt]

@scottdelaney98 I haven't seen shorting, but it would be a good idea to not be as generous with the grease as I was!

[@dustinyeary8266]

Thanks for the video! After a year have you had anymore issues?

[@BartFixesIt]

@@dustinyeary8266 no issues to date!

[@RobertHalstead-i4e]

Great advice.

[@arvielockridge9159]

*Promosm* 😎

[@brianleduc2244]

After time gone by did it still off or did it start back??

[@BartFixesIt]

No - mine was a permanent fix. An unrelated issue with my tailgate button, but no trailer connected/ disconnected issue!