My truck came from the factory with the 4 pin harness. Yellow, green, brown, and a thick black wire.

The connector corroded to dust so I replaced it with a new one. Only difference is the black wire is now a thick white wire...no big deal.


I've never actually hooked up to a trailer and tested the lights but I am trying to install a "fire strip" or led tailgate strip. It plugs right into the 4 pin and should be good to go...not the case.


My volt meter reads around 10V on both the yellow and green wires if a turn signal is on and if a brake is on. The brown wire never gets voltage. I am using the white pin as my ground when testing.


This doesn't seem right to me anyone see where I went wrong?

 

The owners manual indicates that the male pin with the heavy gauge wire (white) is the ground. The brown is a "park" wire whatever that means and the green and yellow are brake/turn lights for each side.


Why would both green and yellow have voltage when a turn signal is on?

 

If the pin corroded, you may have corrosion elsewhere. Inspect the rest of the wiring.

 

park light is the running lights OR all lights ON except for head lights...

the turn lights should have voltage ON then OFF.. like the bulbs...

what year of truck

I have an 04.. my fuse box circuit board went bad. and I lost trailer light circuits.

before you continue... check and see if you have a broken ground wire..

 

Its a 2006. The yellow and green wires definitely didn't have pulsating voltage when I had the turn signal going. I never did have it in drive to check the brown wire since I was working alone.


All the wiring is enclosed in a wire loom would I have to pull it all out in order to check for a broken ground?

 

Yes, if you have a meter.. just check ground wire and the frame or bumper. as frame is ground...

you may have an electronic fuse box... and it may have issues...

or you can just install an aftermarket trailer kit to your tail light system.