Here's my how-to for the Rigid Industries SR-Q Diffused Back-up light kit Part # 98002
DISCLAIMER: I am not an expert, this is just the way I did it and I think it's a good way. Rigid's instructions are actually pretty good and the harness is nicely made so it shouldn't be too difficult.
First of all the instructions. If for SOME reason you don't have the instructions from Rigid, here:
Now lets begin. First lay out the harness on the ground. Make sure all the wires are good with no nicks or cuts.
Then start on the red wire with the fuse. The eyelet connector goes on the battery's positive (duh).
Then feed the wire along the front of the truck slipping it and the fuse under that plastic panel.
Bring it around the airbox, you can bring it under those bolts but no need.
This is where the fun starts. You should have reached the relay by now. The black wire with the eyelet is the ground. Find any spot on the frame to ground it. There's a built in ground on the vertical frame piece beside/behind the intercooler that's really close to where we passed the red wire earlier, but I got lazy and used the firewall.
Now it's time to feed the wires into the cab through the firewall. Instructions say to put the relay under the dash, but I couldn't figure out how to get the relay through that grommet so I just put mine in the engine bay.
Make a small slit in the small "nipple" of the grommet. Feed the short black, red, and blue wires as well as the long white wire through that "nipple". Try to get the relay as close to that grommet to give you maximum wire length to play with inside the cab.
Now, take the long white wire, the two long blacks, and the two long reds. These are all going to the back of the truck. I couldn't find a good place to feed these wires inside of their loom down to the underbelly while on the driver side of the truck. So I brought it across the engine bay through the underside of the wiper cowl. You will need to remove those lower bolts of the cowl to get the wire up in there. I really think it looks nice and factory. Just follow the dots!
To be continued...