when i bought my car it came with a 4 chan alpine amp. i was going to sell it so i took it out. i decided to keep it and am trying to put it back in my car, but like an idot i didnt mark the pos and neg. is there an easy way to figure out which is which without ripping up the carpet?

 

Get a meter and put pos lead to battery and hook up negative to each wire. The negative wire should cause the meter to move to 12v. If you dont have a meter get a 12v bulb and some speaker wire. Hook up one wire from batt to bulb, other wire to the two wires in question. The ground wire should cause bulb to light up. You can remove the dome light bulb or any of the turn signal or corner lights, they are all 12volts.


Ground wire should be connected to bare metal so you may want to trace each wire.

 

thanks, i never thought of the bulb, that makes alot of sense and will save my carpet

 

another really cool thing and good idea, is we have a lil toy, that is a stick of metal with a light, and a ground wire.. you put the ground to metal. touch the stick to the wire the light comes on the wire it "hot" or the power one... no light on either turn the car on try again. its a really cool toy.. easy to figure what fuse blew without have to pull them and such... pretty much what was already said, but its a fun toy.. thought i would share my slightly different idea to it...