Extra Wires

[pmf608]

When I was working on my truck today, I found some extra wires that aren't being used. I had taken the underhood fuse block shroud off to make room to drill a hole in my firewall for my amp power wire. Under this cover, I found two wires and a three-wire plug that were not being used. I was wondering if anyone knows if they have these wires, or if anyone knows what they would be for.

I thought the red wire might be for some sort of accessory like the light in my canopy, but it is too well integrated into the factory harness all the way through inside the truck even for a professional installer to have done it.

The blue wire with the plug I have no idea about - it has the same connecter as my HID headlight ballasts

The three-wire plug also baffles me - I have no idea what would plug into that. I know the picture is not very clear for this one. The wire colors are brown-black stripe (left), black (center), and brown (right)

Thanks in advance for any help.

[Springthing]

Just took an initial look on my '99 and I couldn't find anything that looked like those. It's dark, though, and I was working with a flashlight. Hopefully someone will be able to give you a hand!

[TRPLXL2]

Well I know this isn't going to help but I'l post it any ways, that plug connected to the blue wire is a Delphi Packard connector A.K.A. Gm uses them on everything, hell I even bought some to use for my headlight halo connections! The one wire plug (orange) almost looks like a knock sensor plug, and as far as that 3 wire plug I have no idea. Well if anything this post will bring you back to the top!

[pmf608]

I just thought I would bring this thread back in case anyone else found these wires on their truck and was wondering. I found out while doing some research in preparation to install trailer wiring for all possible functions that the red wire is a power wire for a trailer brake controller and connects to stud 2 in the fuse box. It is on all trucks, and should not be connected unless a trailer brake controller has been installed at some point. The blue wire is the trailer brake output from the controller. It will only be found with an open connector on trucks without the towing package (aka HD trailer wiring), since the LD trailer wiring includes lights and ground only run to the back of the truck, with the brake output left under the fusebox.