So I just got these braking sensors (4 front, 4 back) for my 2002 F150 SuperCrew and I'm in the process of installing them. I've already drilled the holes in the bumpers successfully, everything looks good as far as placement. Now I'm just trying to figure out how I'm going to run the wiring.

I've read multiple places that there is a rubber grommet or something located in the firewall on the driver's side that I can run the wiring from the front sensors through. I'm not 100% sure of its location though.

Also, I'm not really sure how and where to run the wiring from the rear sensors into the cabin. Is there some vent or some hole I can run through?

And the last thing is powering the control box. The way it works is the front sensors are powered by the brake lights when you apply the brakes. The rear sensors are powered by the reverse lights. I'm supposed to splice off of these near the driver's side brake light and then mount the control box in some waterproof box near the back of the truck. I was wondering if there is some way to splice off of these wires earlier on in the line, maybe near the fuse box or something so that I can put the control box in the cab of the truck and avoid the worries of waterproofing.

So basically I'm just asking for any suggestions or tips on this whole wiring process. I'm not exactly sure how or where to run the wiring, I'm guessing underneath the paneling once I get inside the cab. Any help is much appreciated! Thanks!