I have an '04 XLT and the 4-pin trailer connector seems to have a problem. The pins are mounted vertically, and are as follows (top to bottom):

Male - DC Com
Female - Park Lights
Female - Left Signal/Brake
Female - Right Signal/Brake

I can read the voltage between the top pin (DC Com) and both of the Signal/Brakes pins, but the Park Lights pin never has a voltage. I looked through the fuse box and did not find a blown fuse (did not find a fuse labeled for this function in the manual). Any suggestions as to why the trailer parking lights will not work?

Thanks,

Southerner

 

just have to ask
did you check it with the key on or truck running?
and dc com = ground on a car/truck

 

Owners manual page 241

Fuse #10, 20A
Is Relay R201 installed.

Did you check the fuses with a meter on both sides, with the parking lamps on ?

This is the only way to test a fuse, looking at them does not tell you much, aside from how to waste 30 min pulling and checking all the fuses ( all 109 of them ).

 

I tried it with switch off, on, and truck running. Suspect it should work anytime the truck parking lights are on, but not sure.

The DC Com has to be the same as the vehicle for the brake/signal lights to work.

I am wondering if the parking lights for the trailer are run through a relay, and maybe the relay is bad. But I can't find the correct fuse for it, so it could just be a blown fuse.


Will check R201. I checked the fuses with an ohm meter. On second thought, that might not be the best thing since there may be a problem with the source voltage to the fuse. I will re-test fuse #10, also. Yes, I did pull most of them, but did skip some that did not have a description that was relative.

Thanks, I should know something soon!!!

 

Thanks SSCULLY.
It was fuse 10.
Thanks!