Can anyone give me some tips on how to wire something from the rear to the battery, and to the dash for a switch?

My tailgate has a light in it and the wires are following a piece of metal to the front, do I use this?

For the switch, do I push it through from the dash or from behind the engine to get it in the cab?

I don't have a big car lift, and some places want like a hundred bucks to do it.

 

Ok, my personal opinion is get a relay. Wire from the switch to one side of the relay then the battery to the other side.
Then the battery side to the back of the truck.
Here's a quickie diagram that should make it clear as mud.



Get a relay, switch, and wire rated for more amperage than you will need. Also, you may want to put an inline fuse in both sides of this.

 

I think you need to read my post again!

I'm wondering HOW to run the wires.

Clear as mud? You didn't even put the pin numbers lol

this is the schematic I already made

 

My 92 has a wire bundle that runs along the drivers side frame rail I followed that and zip tied it in place.

To get through the firewall punch a small hole though an existing grommet and seal it up with some RTV.

 

Yeah just run them on the frame rail and make sure they're secured to it, easiest being zip ties