drpdmazda
+1y
i think someone put up a sticky about what wires are what, but if someone " re wired " your truck it wont work anyway, the easiest thing to do is this
go to sears, and get a multi meter ( about $25 ) then you can return it when your done lol.
ground the black lead of the meter somehwere, usually in the ignition hole works for me,
then start testing wires, when you find one that reads 12 volts, that will be your memory ( keep the truck off at this point )
you can get ground anywhere, pull the carpet back a little to see if that black wire is actually ground, if it is great, use it, if not you can even make your own, sand down a small spot in the metal near the radio, and use a self taping screw and a star washer, put a small ring terminal on the end of the ground wire and screw it into your metal, now ground and memory are taken care of.
next turn the ignition on, you now have a new ground so you can use that for the multi meter, start testing wires, when you get another one that reads 12 volts, turn the ignition off. it should go to no voltage, if it does that, then you have found your power wire, you may want to put a small in line fuse on that wire, but not a necesity
now to test speakers, general rule of thumb is that the lighter wire will be positive and the darker wire will be negative, but dont quote me, i dont know if your truck has been tampered with. you can do one of two ways, one is pull the speakers and look at the wires on them, if they are factory wires and the factory wires are still in the dash, you can just match them that way, if not heres what you do
get a 9 volt battery ( or a cordless drill battery, 9 volt just sends less of a jolt to your speakers ). your speaker wires will most likely be paired together so look for wires in pairs, then you can strip those wires and touch them to the - and + sides of the battery, make sure its kind of quite so you can hear the speaker pop. if you hear the speker pop you know you have the right wires
hope that helps a little
sorry about the book
good luck