unused wires??

[mp18d]

HI
I have a 2003 F-350, 7.3SD. It is pretty much bone stock. I was beginning to install a set of factory fog lights. I looked at the wiring loom on the driver side firewall, and noted 4 deadend wires coming out of it. They are red, blue, white and black. I bought the truck used but these look like they have been there since new.
They are not terminated in any way. None of them are "hot" with the key on.
Any ideas what the heck they are???

Thanks
Mike

 

[DaveBen]

They are unused wires for you to use as you see fit. They go through the fire wall and end just on each side. Look for them inside the cab of the truck and in the engine compartment. They are free.

Dave

 

[mp18d]

Aha, so that is what the little pamphlet meant by "pass thru wires".
I could not figure out which bundle was the dimmer switch harness, but I figured if I just put the wire from the fog lite harness that was supposed to go to the dimmer switch to a hot lead, it would enable me to turn on the fogs anytime???

Thanks again
Mike

 

[dieselpilot]

You could use one of the customer convenience (pull through) wires to control the relay that powers your fog lights and place a switch in the cab somewhere. I wouldn't recommend powering your lights directly from the switch, just use it to control a relay and power the relay from another source, like one of your batteries.
Cheers

 

[W4RLR]

If they look like these, those are your Customer Convenience Wires as Dave said.

Not sure where they terminate inside on your truck, but this is where they are on my 2005, above the brake pedal and to the left, near the parking brake pedal assembly.

Good luck and have fun!

 

[mp18d]

Those pass thru wires are a great idea. Thanks to all for the help!

Mike