I have a 2017 F150 xl supercab, and I'm looking to install an emergency light bar on my backrack. I want to run my wiring into the cab, not along the frame, (and yes I have tried multiple attempts with the forum search bar and have not been able to find any results on gaining access to the cab). I was able to fold down the back seats and the only thing I can find to run my wires through is the rubber shutter vent on the driver side. Anyone know of a better access point? I really don't want to drill any holes and the wiring is to thick to go in between the doors and weather strip.

 

Hole - grommet - done

 

You can access under the passenger side area on the floor. Watch this video this guys did for adding truck bed lights. You can do the same for your use case. If it was me though I’d drill the hole in the back where it’s convenient for your use case and add a rubber grommet.

https://www.f150leds.com/products/15-18_cargo_light_led

 

If drilling a hole, I would even consider using a through-hull cable fitting made for boats for a real good watertight seal.