trailer lights wiring trouble

[txneal]

Hoping one of you guys with electrical knowledge might be able to help me out with troubleshooting suggestions. My problem is that the wiring on my truck for the trailer lights seems to be fouled up. All I am getting is a left turn signal. I am sure that the problem is with my truck because I had a friend hook my boat trailer up to his truck and the lights all worked fine. On mine, I get nothing but a left turn signal.

I have inspected the wires and they all look good as far as i can tell. I have also thouroughly cleaned the connection to make sure it is making good contact. In addition, I hooked up to an additional trailer and got the same results...nothing but left turn signal.

My truck is a 2001 F-150, King Ranch Edition with 4x4 and trailer towing package. Where do I need to start looking next? all of the lights on my truck are working perfectly; it's just the trailer lights that are giving me trouble. Is there a fuse or relay or something like this that I need to check and where would this be located? I have very little experience with wiring, so any suggestions will be helpful.

 

[redbug]

Get yourself a test light and check to see where your trouble is. you said they look good but they may still be faulty.. If you don't want to go the est light rout I would remake all the connections on the trailer wire harness

Wayne

 

[txneal]

well, the problem is actually with the truck and not the trailer. If it was the trailer, I think I would jsut install a new harness, but the trailer wiring is fine as it works perfectly when hooked up to my friend's truck. I have checked with a test light at the connector on my truck and am only getting power to the left turn signal, yellow wire...the other two wires are getting nothing.

 

[redbug]

I understand that your truck harness is the problem.
do the lights on your truck work? is so I would check the connections were the trailer plug joins the truck harness and remake those connections


if you work your way back from the plug with the test light and find your bad connections..

 

[Quackrstackr]

If there are fuses, they will be identified in the owner's manual in your truck.

If it is not a fuse, you will have to use that test light and start at the plug then work your way toward the front. I'm betting that the plug where your trailer harness connects to the main wiring harness on the truck has either come loose or is otherwise faulty.

redbug beat me to the post... :lol:

 

[txneal]

OK, thanks for the input. I'll crawl under there this evening and see if I can determine where the problem is. I pulled another trailer a couple of months ago and the lights were working fine at that time, so I guess something has recently come loose.

 

[masterofillusion]

I just stumbled across this. I have a 2002 king ranch with the same problem. It has beat me. I can not figure it out. The only trouble Ive had with this truck is a leak in the windshield. The dealer had to replace some electronics under the dash, under warranty. The trailer never worked after that. I even ran separate wires from the truck lights. Everything seems fine until I plug the trailer in, then It goes haywire :? Please let me know if you find the problem. Thanks

 

[Macgyver]

it's fuses in the power distribution box under the hood . all the trailer wiring is separately fused from the truck lights.

 

[Loggerhead Mike]

what kind of wiring harness does your truck have? a 4 pin or the new style 12pin?