trailer lights wont work, 4 pin harness gone... - Diesel Forum

weraracer · 03-19-2006, 11:25 PM

well when i bought this truck someone must have cut the 4 pin harness off and just taped up the wires. i had assumed the 7 pin would still work, but it doesnt. none of the trailer lights work. is there something i need to rewire etc to get these to work? oh its a 03 6.0, thanks.

Berol · 03-20-2006, 07:58 AM

Have you checked fuses?

weraracer · 03-20-2006, 09:09 AM

well not yet, it was late last night and i assumed that the 4 pin hack job would have been the cause. i will get a closer look today. thanks.

obonaventure · 03-20-2006, 03:16 PM

Are the wires that are taped up shorting out each other?

short_stuff · 03-20-2006, 08:54 PM

If the 7 pin plug wasn't used by the previous owner, it may need the relay added to the fuse panel under the hood. When I ordered my truck with the towing package, the 7 pin adaptor came in a bag with the light relays in the glove box. Still there, as I haven't had to use the 7 pin plug yet.

weraracer · 03-20-2006, 09:36 PM

i would say it was used since he had a 5th wheel in the bed. i checked the fuses and they look fine. i need to pick up a test light and see if there is any power at the plug.

weraracer · 03-20-2006, 11:14 PM

i amnot getting any power to any wires in the back. the fuses look good, relays are there. any idea what to check next??

Down South · 03-21-2006, 09:56 AM

If the previous owner had a fiver hookup then he may have had a in bed connector for his trailer. It's pretty common for folks with fifth wheels or goose neck trailers to do that to keep the trailer wiring from draping over the tail gate. Is there a connector in the bed of the truck? If so he probably cut the wires going to the connector at the bumper instead of splicing into them.

weraracer · 03-21-2006, 10:42 AM

hmmm, i have had the truck for 1 year now, and there isnt a plug in the bed, but there may have been at some point. would he have possible cut the wires further up in the system? the 4 point harness at the rear was certainly cut off (like someone needed one and took it) but the wires were not grounding out and were just blunt ends). i guess i will need to trace the wires back to the cab and see if they have been cut. thanks for the reply. if there are any other ideas, please post, thanks.

weraracer · 03-22-2006, 09:49 PM

alright so i played with the wires tonight. they arent cut anywhere that i can see up along the frame. the power comes sometimes and they work fine, then other times, most of the time, there is nothing. i jingle the wires around and nothing changes. i have NO IDEA what the problem is - maybe a bad ground???

i have an ABS sensor out in the rear, is that tied in somehow??