Ok so I bought a refurbed headunit for my Pathfinder cause the old one was crapping out, and me and a friend thought we could do the wiring no prob but we can't get it to work. He thinks our wiring is fine and the headunit is busted, I'm less confident in the wiring but is their anyway to test just to see if the headunit is working without having to rely on the wiring being correct? Like hooking it to a battery or something?

Thanks

 

Get its manual and figure out which wires are for power (switched 12v & ground). Just hook up those and see if it powers on for starters. You could do it in your house with the use of a radioshack dc converter.