I'm a new user and posted this on the announcements site, but not sure what kind of response I'd get, so I reposting here.

I just installed a jason topper on my 2003 F150 Supercrew 4x4. I've seen several posts on the 3rd brake light feed (green wire off harness), so that problem is solved. Now I'm looking for a power lead in the back for the cargo light. I have a factory tow package and was wondering if I can tap into the 7 pin harness. If so, which wire?

 

I'm suprised you don't have a bunch of help by now. I would tap into the power to the seven pin. I don't know which wire it is but it would be the hot one. You are also going to need a ground also. If anyone has a better idea I'm sure they will wade in.

 

You would what the black wire, This wire is only hot when the key is ON though. I have also seen people run a wire right from the battery down the frame to the back of the truck, this way you can turn the light inside the topper on regardless of key position.

 

Thanks for the replies. I'm also suprised that I didn't get more of a response, but yours is enough to help. I think I'll just run a feed from the battery and be done with it.

 

that's what I would do, don't forget to put a fuse in line.

 

How do you want to activate the light?

Stand alone switch.
On when cabin light goes on.
On when you open door.

I say use a cabin mounted switch and activate the light only when needed.

How do you plan to use the light inside the topper.