alnen

I have a 95 f150 with 5.0 and auto tranny. I rented a trailer today, but was not allowed to leave the lot because none of the trailer lights worked. I tried hitting my brakes in and out of gear, turned my headlights on, tried turn signals, etc. and nothing worked. Trailer lights worked fine on other vehicle.

I got home and tested the connectorand got nothing from the test light. I tested all the fuses and everything was good (distribution box under the hood, and the one under the dash. The wires at the connector were all cut up and spliced. I fixed them, but still get nothing. I followed the harness to the front of the truck and tested along the way. I got no power from any of them as far as I could follow them, with the pedal pressed and them without.

I didn't see any grounds to check. Is there a fuse box I'm missing? I need help!

adamst

Your trailer lights run off your tail light harness. So if you have no power thru the 'harness" then u shouldnt have any brake, tail, or blinkers in the rear of the truck. If your running a 4 wire flat or a 7 pole you can buy a adapter that simply plugs into your tail light harness it just goes in between the harness plug that branches to each tail light. hopkins makes the simple plug you can buy. I hope this kinda made sense to u hard to explain.
Try this link http://www.hopkinstowingsolutions.co...350_87-98.html there is installtion intructions on the page that will show you were the plug is and give you a idea where to test at to see if you have power.

If the link doesnt work just go to the website and punch in your year make and model.

alnen

What I saw underneath my truck were two round connectors. One had the same color 4 wires as the trailer connector, black, green, yellow, and white. This is the connector that the trailer harness is connected to. The other round connector is also round, but only has 3 wires and not the same colors as the other. It is not connected to anything, just dangles there.

Is it correct that I would need the harness you mentioned to connect in between them? I know my brake lights, tail lights, and blinkers all work, but I have had problems with my cruise control also and I think this may have something to do with it.

ngraham2010

did you check the relay for the trailer lights also

alnen

No, where is the relay? The box under the hood isn't marked.

Warlockk

It sounds like a PO installed a light harness that isn't working. The 3 wire sounds like a connector for a break controller. You can either go the easy route and plug in that T tap nice and clean or try to trace down where the PO hooked up the wiring and why it doesn't work.

ngraham2010

Those two round plugs are the factory trailer package, heres the under hood fuse box
http://www.f150online.com/forums/mem...ompartment.jpg

alnen

Resurrecting this thread... I removed the POs trailer harness. I went to autozone with the aforementioned part #, and upon lo looking at the connectors, they were wrong. I looked through all the harness kits, and did not see what I need. What is on my truck are 2 round connectors. The drivers side has 4 pins in a round pattern, and the passenger side is also round but has 3 pins (same pattern, just one less pin).

Looks like I will just have to hard wire a trailer connection on. Can someone tell me what connector to get, and how to wire it? Thanks so much!