1971 Ford F-100 - Mysterious orange wires under hood

[Montana71-F100]

I pulled the 360 engine out of my 1971 F100 about 5 few years ago and overhauled it a couple of years later and I don't remember where an orange wire was connected. It goes from a wire bundle between the brake cylinder and the wheel well and runs beside the rubber windshield washer hoses. It was cut about 8 inches after it reached the passenger side window washer. I've been driving it for a couple of years and everything seems to be working fine, but the wire must have a purpose. Does anyone know what it is supposed to attach to?

Also, from the same bundle there is a female connection to an orange wire. What is supposed to be connected to it?

Thanks,

Steve L.

[fordman]

orange? probably some emmisions junk. EDIT: fuel guage sending wires are orange aslo. they will go to the in cab tank up inside the roof and down both pillars on the drivers side and to that take. they will also go out the firewall and down the firewall back to the aux tank or now days called the midship tank. or its emissions wires.

[Montana71-F100]

Thanks for the reply. I'm pretty sure it's orange. The wire is faded but I moved a piece of black tape that held it in the wire bundle and it looked orange. Being emmissions junk would explain why everything seems to be working fine without it being connected to anything.

[Montana71-F100]

My curiosity got the best of me and I decided to trace the orange wire that was beside the washer hoses.

I thought it went through the firewall but when I removed the tape that holds the bundle together by the brake cylinder, I found that it was spliced to a black wire that goes under the truck to the frame. I traced it to a an intersection under the front driver's side of the box where it is tightly wrapped and tied to a hole in the frame. Two wires go up to the inside of the left side of the box and others go to the back of the truck. I didn’t want to unwrap the wires but now I know that the wire either has to do with power to a camper or to lights on a trailer.

[fordman]

it shouldnt be stock camper wiring on a f100. the last f100 camper special was made in 67. has it been added to the system? if so then it could be for a camper or something.

[Montana71-F100]

That's interesting. The attached pictures show the wires in the bed and the wires under the hood. The rubber bushing that the wires go through in the box and the stamped area around it indicate that it was done at the factory. I suppose it could be ment for a topper rather than a camper.

I used an ohm meter and an extension cord and found that the black wire is the one connected to the orange wire under the hood. The lighter wire is the ground. The orange wire under the hood ends not far from a black wire that goes to the light in the center of the underside of the hood. The orange wire may have been spliced to it at one time. I thought I cut the black wire there when I removed the hood when I overhauled the engine.

The truck was a year old when my father bought it so the orange wire could have been added by the previous owner. I don't ever remember having anything hooked up to the wires in the box.

[fordman]

now that is different than what i have seen before. is this truck a rnager xlt or an explorer model? that may explain the extra wiring. i know the hood light is a ranger xlt and explorer package upgrade. or i mean it came with htose two special packages. it could be that wire did go to the solinoid on the fender and provided a light or something back there.

[cep62]

The rubber grommet is originally for access to the side trim screws.
But it is a good place to run wires.

[Montana71-F100]

It has a "Custom" emblem on the back. I just looked and there is a grommet on the opposite side too. This particular truck doesn't have molding but if molding slides over holders (or whatever they're called) and is held in place by one screw, that would make sense. The way the wires are tied and wrapped, it looks like the wires to the back of the truck for trailer lights and the ones to the box were put in place at the same time.

Attached are pictures of the truck and of the light under the hood.

[fordman]

its wierd that i thad a light under the hood unless it was special ordered with that light. yes my truck bed have that gromet. it was just wierd that i had the wires coming through it.

[Montana71-F100]

It's a pretty interesting light. I couldn't find a button that would turn it off when the hood is closed so I was worried that it would be on all of the time. I closed the hood slowly and I saw that it turns off when the hood is nearly closed. It must have a mercury switch.

[fordman]

yes the mercury is suppose to be in the base of the socket. i got one of those awhile back from the junkyard. but the wire had been damaged. it is fixable though.

[Montana71-F100]

I think you'd like it if you install it. In case you aren't sure how to connect it, mine is connected to the battery side of the relay that goes to the starter and has an in line 9 amp fuse.

[fordman]

yes that is where i found the other half of the wire. i am going to put it on my 68.