There are two factory wires running into the front speakers: one red, one blue. Which is positive and which is negative?

 

It doesn't matter as long as you are consistent with how you wire it from the headunit.

 

Well, I'm going to be tapping into the harness behind the headunit with the wires from my amp (to use the factory wiring from that point out into the doors), and I think the wires go through other connectors and change color or something between the HU harness and the doors, so I need to know which is +/- as they are wired from the factory.

 

to check which is - & +





take a 9 volt battery



take your midrange speaker out of the door
it will unplug
but don't unplug it
cut the both wires that run from the plug about 2" in length

now you shold have speaker out of car and in hand
the factory plug should still be attatched to speaker and you should have left 2" of wire coming from plug
strip 1/4" off each 2" lead

take your nine volt battery and touch at the same time one color wire on the + terminal and the other on the - terminal

when the speaker moves out NOT IN than you have found out which color wire is - & +

if speaker moves in than switch wires and now it should move out

 

^ +1 9volt trick is sweet

 

Huh, cool trick; I'll give that a shot. Not I just need to find a 9V battery laying around somewhere...

 

Worked like a charm!

Red = Positive

Blue = Negative