Hi folks,
New member here. My trailer wiring (on the truck, not trailer), is pretty old and when I hooked up my harness to the trailer I found out that the yellow wire was dead. A few years ago I had to splice and meret a new harness on. I just checked out the connections at the merets and they were pretty corroded so I peeled back the wire sheeth a few inches only to find the wire was black. The white ground wire was the same (burnt) although the ground is still effective as the right trailer signal is still working. I checked the fuse and relays, all seem to be fine. Any advice on what the cause could have been? I did sink the rear of the truck in water awhile back (long story) so I suppose that could have caused the wire to burn? Is there anyway I can replace the yellow wire without rerunning to the front of the truck? I tried finding a schematic to see if there is a connector module somewhere but I haven't had any success (2009 F150 XLT)

Any assistance would be appreciated.
Cheers
Craig

 

Dunking in water clearly would cause issues.

 

I agree. Caused several for me unfortunately. I'm hoping there is a disconnect somewhere near the back so I can juat replace that section of wiring as opposed to running an entire new length.

 

What is "meret"? Post pics, as described at this link.
http://www.supermotors.net/forums/th...-and-or-videosThat's not "burnt" - that's a layer of Copper corrosion.If you mean while the trailer is hitched to the truck, then it could be grounding through the tongue/ball/receiver. If it works with ONLY the wiring connected, then the ground wire could be OK.Fresh or salt? How deep? For how long? Did you wash the undercarriage off thoroughly afterward?No, 12V is not enough to burn a wire, even in salt water. If it was, it would have blown fuses first. That's the purpose of the fuses: to protect the wires.

 

Thanks for all of the info. This morning I was able to find the disconnect above the spare. I've attached a pic. The connector contacts look in good shape so I hope the corrosion/burnt wire issue was isolated to the harness. Also, to answer the inquiry above, I had mispelled Marrette (twist on wire connectors). You can see where I had to attach a new pin connector a few years ago. I believe this is where the issue started (connection). Hopefully the new harness does the trick.

Thanks again!

 

I don't see anything twisted on in your pic - it looks like there are several crimped butt splices. And I don't understand why so many of the trailer wires appear to be spliced into each other.