"Trailer Disconnected" message

[PrairiePete]

I just returned from a three week trip to the east coast pulling a 20' Airstream with my 22 XLT 3.5 Ecoboost w/ tow package.

Almost every time I reconnected the trailer I got a series of warning messages: "Trailer Disconnected". Sometimes I would rapidly get two or three of these in a row, separated with a message about the trailer brake gain.

I can't tell which of the seven connectors isn't working well. The running lights, trailer brakes, turn signals all work as expected. Twice I got an additional warning that the trailer battery wasn't charging, but I was unable to determine if that was true or not. I have cleaned the connections as best as I can and I have tried wiggling the connector to see if I could reproduce the error, but no joy.

Assuming that this isn't an F150 electronic glitch, does anyone know which contact the truck monitors for this warning? At least I could narrow the problem down. Thanks in advance.

Pete

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[powerboatr]

i have to ask
what is the condition of the trailers battery that feeds the emergency breakaway. if its separate from rv battery, check its charge.
if it shares the rv battery, make sure the charge line is connected and receiving voltage from truck when plugged in and truck is running
also the ground on the rv to the frame via the 7 pigtail. the system is very picky about grounds really picky
those 2 critters will screw with you for days

then i would look at the trailers pigtail to make sure its clean and no corrosion on the blades that engage with the truck

 

[PrairiePete]

The breakaway switch is connected to the house battery (200 AHr LiFePO4), which ranged from 68% to 100% depending on how many days we had been dry camping.

The house battery was fully recharged on each travel day, so I can assume it is connecting to the truck. I just don't know if it is continuously connected.

If I understand what you are referring to, the ground connection from the 7-way to the rv electrical system appears to be fine. It is inside the body of the camper, connected to a buss bar that connects to the rv's frame at multiple locations. Everything except for the F150 system is functioning normally.

I have cleaned all 7 contacts as well as possible. My next step is to replace the 7-way if I can't figure out which contact is causing the problem. That probably means replacing the whole cord because I can't find high quality replacement plugs.

Thanks for your input.
Pete

 

[powerboatr]

e trailer has the whole cord

using the rv bus bar as the ground is a good thing
it may be more of an issue,
this system has been ground sensitive since day one back in 06. sometimes TOOOO sensitive
iirc the tsb on the brake controller made some changes to sensitivity, .
it can cause you to pull your hair out real fast

might want to ohms check the cord and the frame grounds to make sure

and you did check the fuse for trailer battery charge right? as well as ensuring the truck harness is fully seated into the plug at the bumper.
all else fails go see dealer and have them load test the truck connections t check the system
good luck

 

[PrairiePete]

Thanks. I'll have a go with your last suggestions.

Pete

 

[Howdy_1983]

Myself and my co workers have had water get inside the connector from where the harness enters. The connections where they attach to the terminals were corroded and causing the same issue. These were on F550s though, not sure if a 22's 7 pin is the same or not. (we were able to take them apart and clean them off)

 

[Davexxxx]

I don't know when it started but trailer connection gremlins is a thing in modern trucks.

As far as I know, GM was the first. My Brother in law had fits, getting communication established when he got a new GMC. Old truck worked fine, new truck would throw errors. New truck would test OK at the dealer. Working from memory now but it wasn't normal connection corrosion or fit of the plug. It was, as I recall, something in how the brakes were wired, messed with the computer that had to be tweaked and was wide spread enough to become a known issue.

On Fords, as Powerboatr mentioned, the new systems are so sensitive any little thing causing any sort of differential, makes the computer unhappy.

 

[mj1angier]

May not be an issuer with 7 pin but in the old flat connectors if your ball is rusty (there's a joke in there somewhere..) it will keep the truck from making a good ground connection from truck to trailer. Normal goes away after a few miles/ turns.

I do keep a can of contact cleaner in truck and give them a shot before hooking up
https://www.amazon.com/Hosa-D5S-6-D...86-889d-9c318b27a576&pd_rd_i=B00006LVEU&psc=1

 

[RickBullotta]

If I recall correctly, there was also a software update for this issue. Some LED lights (like those in modern airstreams) didn't generate enough current draw to reliably indicate connection status. Not 100% sure of this, but I remember reading about it. Also of course keep those connectors clean and corrosion free (both sides of the 7 pin connector). I also add some dielectric grease to help keep them cleaner, and I also cover the Airstream side of the connector with a cap when not in use.

 

[Ian1643]

Had the same problem on my 2022 f150 with tow pack on our first trip. The first time it happened I stopped to make sure the trailer was still there then finding that it was checked that everything was working. It must be a glitch in the software because I just kept hitting OK on the wheel and it went away.

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