How to run a wire from inside of a cab out to the back???

You can also run a wire under the carpet to the sleeper bunk and drill a little hole in the floor under your bed to get the wire outside

 

Just go to a Home Depot, get a cheap drill and do that little hole yourself. Why do you need someone else to do it?

 

Look from underneath the cab and drill in the empty space, there is nothing important under the sleeper bunk storage area. Everyone usually installs bunk heaters in that compartment.
You can install a rubber grommet if you want Advance Auto Parts - Down for Maintenance
but there wont be much moisture getting in, because you are drilling just a little hole for the wire size. You also can pour any kind of sealant around it

Then when under the truck, zip tie that wire to just about anything

 

The way to do it.

 

Seriously your making this so much harder than it has to be. Go out through an existing grommet in the firewall then down under the cab to the back. Your going to have the screen mounted up front anyway. Kiss applies. Keep it simple stupid. Going out the back of the cab will be way more work hiding the wire.

 

Would you mind telling him what brand and model for the wireless cam. I just picked a random waterproof cam from Amazon. Did not do any further research. Nothing better than a review by an actual user. Not an Amazon review where people give things 1 star because they had difficulty opening the box. Thanks in advance @Ridgeline #Ridgeline