trailer light problem

[mprobst]

Tthe running lights on my trailer work, but no brake or turn lights. Turn and brake lights work fine on the truck. Checked with a meter at the connector, so I know it is not my trailer. I found this info in a search, but the fuse is good. Does it go to a relay or another fuse anywhere?

"This info is from a 2003 superduty diagram, so I hope it's the same.

The left and right turn come from fuse #6, 20 amp in the underdash fuse box. "

Where else can I look? any suggestions?

[SuperCrutyPS]

When you say you checked the connector, you did or did not find brakes and turns there? I'm not clear there - I may be dense.

[mprobst]

I could only get voltage for the running lights at both the 7 pin and the 4 pin connector on the back of the truck with my meter, nothing for brake or turn on either 7 or 4 pin connector, so I am guessing it is a fuse or something further back in the harness. they just stopped working last weekend, worked fine the weekend before. checked with a second trailer and same results, only running lights, no brake or turn.

[SuperCrutyPS]

Here's a link to a webpage where you can view the 2003 Owners Manual.
https://www.fleet.ford.com/maintenan...ls/default.asp

Page 178 show the fuses. #6 does go to the Trailer Turn/Stop relay, but the diagram shows 10 relays and they're listed at the end of the fuse list, but none of them are a turn/stop relay. May need to consult a repair manual or call Ford to ask where it might be.

Sorry - That's probably not much help.

[mprobst]

thank you for the link, that will be a big help to have the manual, nice to see ford is making it available for free