I recently purchased a topper for my 05 f150 Supercrew. I am trying to figure out the wiring for the 3rd brake light and the interior light. I have read that there may be a lime green wire looped somewhere in the wiring harness by the rear driver side brake lights. I did some searching but couldn't find it. Can anyone shed some light on this for me?

 

Hi,
I am having the same problem. I have to wire up the brake light on my cap and cannot find the "green" wire that is supposed to be coiled in the rear bumper harness. Mine is an '05 STX with the towing package.
Any help would be so appreciated!
Tom

 

Hi Tom,
I finally found the wire and it works great. Here is where I found it on my 05 f150 Supercrew. If you look under the truck right under the drivers door, you should see a black plastic shroud. (mine was full of dirt so watch your eyes) Under that shroud there was a bunch of wire harnesses and plugs. After looking around in this group of wires I was able to find the lime green wire with a black cap on it. I cut the black cap off and spliced in a new wire back to the topper. My wire path followed the main wiring harness that was already in place. For the interior light on the cap, I tied it into the license plates lights. This way, it only works with the lights on which hopefully will keep me from leaving the interior light on and running down the battery.

Hopefully this helps. Let me know.
Bruce

 

Hi Bruce,
THANK YOU!!!!!!!!!!!!!!!!!!! I found it just where you said.... All run, hooked up and working...

Take care and thanks again!
Tom

 

Am glad you two newbies had success. Stick around and learn or help others as is this case. Never to old to learn new things, as I am doing every day on this site. Don't be a drop out, keep in touch.

 

I thought I'd also comment, glad you guys found the wire. My 05 F150 Super cab didn't have the wire in that spot, mine was under the drivers door sill plate all neatly coiled up. You would think they'd all be in the same spot. But I'm just a maintenance tech not a design engineer!!

 

If you remove the brake/tail/reverse light housing you will find the lime green, black and brown wire going to the brake light bulb. If you figure out which 2 wires control the brake light please let me know. I'm trying to do the same thing on a 2006 model.

 

So when you say it was uder the drivers door sill plate, is that just the black ribbed piece of rubber that runs under the doors? If it is how far back does the wire run, does it follow the harness or does it end in the door?