another 2002 trailer harness problem

[fifty]

Sorry guys. I tried searching to no avail.

I have a 2002 F-350, it has both the 4 pin and I guess the round 7 pin connector. I just bought a brake controller for it...plugged it all in and no brake lights or turn signals.

Checked the fuses and relays, all good...

Took a test light to the round connector on the hitch. It has power for the hot...And thats it...

Any suggestions other than get under the truck and start tracing it all the way back.

Please feel free to ask questions as I do not know what info to offer up to help narrow this down!

Loved to get this working to keep the chippies off my butt...(and to be able to use the trailer brakes...)

[Dietoremain]

dare i say, did you try scraping the contacts on your plug, mine were corroded(no cover) and i cleaned them and voila they work.. lol just saying..

[HaysKSFirefighter]

Try checking the plug under the bed where the harness plugs into the truck's lights. Mine had cracked and was packed with mud. I cleaned the crap out of everything, put some grease in there and then electrical taped the crap out of it. That would be my suggestion, I would also double check the fuses for the trailer lights. I had a bad wire on one of our trailers that grounded out which blew a fuse and was a hell of a pain to find.

Hope you get er figured out!

[fifty]

Cool, Yeah I scrapped the connectors thinking they may be corroded. No luck. They look pretty good too.
I will check the harness. Youre talking about the one under the tail gate area right?

I will recheck the condition of the fuses as well (good idea, I only looked to see that they were there)
hmm...I will advise of my findings this afternoon.

[Handyholmes]

Look under the hood on the driver's side fender. There are 3 or 4 connectors with hundreds of wires going and coming. You will find your broken wire in there! I am on my second 2002 and they both had the same problem you are describing and I found broken wires there both times. The insulation wears through and corrosion destroys the wires. The only fuse you need to check is #6 it sends power to the relays on the drivers side fender that in turn sends power to the rear for the trailer lights. I guess make sure you have the relays first!

[fifty]

Alright. Going to check all these suggestions as I still have the problem and really need to tow...
All relays and fuses are good. I am going to start tracing the wires back from under the truck...(they disappear from the fuel tank to just under the drivers seat...how fun)

I just read in the chiltons book that there is another fuse box behind the glove box. Any need to look there?

I will also get a step stool and spend some time looking at those harnesses in the engine bay...I hope they arent messed up...

[fifty]

Ok just for poops and giggles I decided to recheck fuses...Handyholmes you are my savior! I could have sworn I checked #6 a couple of times...It was blown. (seems I only check #38 carefully and flew through the rest before)

Problem solved.

[rmb1393]

where did you guys mount your harness? and do you have a picture? sorry im new to this and im rigging my truck for towing this weekend