Hello Friends!

I recently bought a trailer. I have never pulled a trailer with my truck. When I hooked up the trailer lights, the tail lights don't work. The turn signals work. The brake lights work.

I hooked up the trailer hitch wire tester and the signal light for tail lights did not light. All the others did light.

All lights work on the trailer when hooked to my other vehicle.

I traced the wire from the plug and it goes into a huge bundle of wires, and it is covered with grime.

I am considering pulling a new wire back to the plug.

Does anyone have a diagram of the wiring and know what fuse it is on?

Thanks in advance!

 

Could just be a bad contact, since you haven't pulled for a while. Did you take Emory cloth or diamond grit needle file to all the contacts on the truck and trailer connectors?

 

These diagrams might help.

 

Thanks! Looks like I need to look for the dk green with yellow stripe wire and fuse 4.

 

I replaced my 4-pin connector and got one with a rubber cap. When I don't use the trailer, I have dielectric grease in the cap and I keep the cap over the pins. The dielectric grease is very effective at protecting the pins from moisture and the connector has lasted me a long time.

 

Not that the information provided probably got you to have conclusion to the pinout, but RVTech spoonfed me back in January on same subject. Was trying to write truck up so it would feed juice to batteries while in tow, that were trailer mounted..guy knows his stuff, greaser😉...

 

Cool! I need to check that wire and see if it is good and therefore just need a new 4 pin connector or if I need to run a new wire back from the fuse panel. Thanks for the help everyone!

 

Maybe find something in this thread, veg

https://www.ford-trucks.com/forums/1...batteries.html

 

Your trailer wires come off of the harness at the rear of the frame. There is a short harness from the frame to the trailer plug(s). I would check there first.

This picture is upside down but the large connector mounted to the frame is the place to check. If you get trailer lights there your main harness is good. I do not have the pin out for it.

 

If you end up replacing the connector on your truck, I will note that a Pro trailer place can easily mount one right in the bumper, with cover, etc. I regularly mangled previous connectors that sit on a bracket hanging down below the bumper, and the connection points, etc., were far more exposed to road grit and weather and such.

 

Nowhere did I see that you checked fuses. I know from experience that the 02, and probably several others, are fused for trailer taillights through the reverse light fuse. I had a short in the reverse light cicuit that would blow the fuse and kill my trailer taillights. Sorry I don't have the manual in front of me to tell you the fuse number but I highly suggest you check that before running wires.
Good luck.