1500 wATT Invertor?

Best way is to get some heavy duty wire (think same as jumper cables) and run it to the batteries in your truck. If you can, drill a hole in the floor of the side box and run the wire through there into the bunk and hook up your inverter. Remember, Red possitive, Black negative.

 

Don't forget to get an inline fuse or circuit breaker to install with the wires for JIC purposes. Should put it in line as close to the battery as possible.

 

I wired mine with welding cable it will take a lot of abuse

 

yea wire it with the heaviest gauge wire you can find like for high power stereo amps (0 gauge).you should ongly need like 5 feet or less cause most rigs have the batteries right there on the drivers side and just make sure you also buy a fuse holder with a rating for how many amps the inverter needs.usually like 100 amps if you have a big one.
Also make sure you mount the inverter somewhere, do not leave it loose in the truck! It will short and could start a fire if you didnt put the fuse in the wiring!