noteven
Apr 17, 2021Explorer III
Ford experts - rear turn signal output to trailer stopped
I have an interesting issue today on my 2012 F-350 chassis cab model.
Quick background - when the up fitter installed the flat bed body, light connections were made to the correct wires for body lighting.
Trailer 7 way connector was wired in to the correct chassis trailer wiring.
All as per Ford body builder electrical manual.
The truck and trailer wiring has functioned properly for 18 months.
Last week I towed a trailer for someone else using a 4 to 7 plug adapter. The info center alarmed a "trailer disconnected" "trailer connected" message of and on for 5 or 6 times - the trailer lights were ok and not disconnected...
Today I connected a new to me enclosed trailer. The trailer lighting functioned properly on the previous owners Nissan truck. It functioned correctly on my Dodge truck last fall.
I connected the Ford to it and there was no right turn signal on the trailer.
The LED right turn signal on the headache rack on the flatbed flashed, the 2 at the rear of the truck bed did not.
Left side OK, tail and brake lights all ok. Front turn signals and mirror signal lights ok.
Disconnect from trailer all truck lights work properly.
Connect truck to a second trailer.
No turn signals work at all at rear. Mirror and front lights work.
Disconnect second test trailer.
Now no turn signals on the truck flatbed work at all. Mirrors and front turns work.
Turn/stop fuses are ok in cab fuse box.
I understand there are relays for the trailer turn circuits in the under hood power center. I have to get back in to the electrical manual to see if relays exist for body lighting.
Park and clearance lights work fine on the flatdeck and cab.
It is like a module of some kind has turned off or possibly failed. There are no error messages on the info center on the instrument panel.
Anyone experience such a step by step failure?
Signed
Confused by Fords sometimes..
Quick background - when the up fitter installed the flat bed body, light connections were made to the correct wires for body lighting.
Trailer 7 way connector was wired in to the correct chassis trailer wiring.
All as per Ford body builder electrical manual.
The truck and trailer wiring has functioned properly for 18 months.
Last week I towed a trailer for someone else using a 4 to 7 plug adapter. The info center alarmed a "trailer disconnected" "trailer connected" message of and on for 5 or 6 times - the trailer lights were ok and not disconnected...
Today I connected a new to me enclosed trailer. The trailer lighting functioned properly on the previous owners Nissan truck. It functioned correctly on my Dodge truck last fall.
I connected the Ford to it and there was no right turn signal on the trailer.
The LED right turn signal on the headache rack on the flatbed flashed, the 2 at the rear of the truck bed did not.
Left side OK, tail and brake lights all ok. Front turn signals and mirror signal lights ok.
Disconnect from trailer all truck lights work properly.
Connect truck to a second trailer.
No turn signals work at all at rear. Mirror and front lights work.
Disconnect second test trailer.
Now no turn signals on the truck flatbed work at all. Mirrors and front turns work.
Turn/stop fuses are ok in cab fuse box.
I understand there are relays for the trailer turn circuits in the under hood power center. I have to get back in to the electrical manual to see if relays exist for body lighting.
Park and clearance lights work fine on the flatdeck and cab.
It is like a module of some kind has turned off or possibly failed. There are no error messages on the info center on the instrument panel.
Anyone experience such a step by step failure?
Signed
Confused by Fords sometimes..