2005 Dodge Ram 1500 Stereo Wiring

I was wondering if anyone knows what wire is what for the front and rear doors of my 05 dodge ram 1500 quad cab w/out the infinity system.  I just need to know which wire is + and which is -.  Thanks, any help is greatly appreciated!If it aint broke, fix it anyway!

Thanks!  I really appreciate it.If it aint broke, fix it anyway!

a way of testing polarity is to keep the plug that goes to the factory speakers, plug it back into the speaker, and take a small battery ("AA") and touch the wires to the poles of the battery and look at which way the speaker moves.  If it pushes out, note what wire is on the positive pole and that is you speaker positive...if it sucks in, then reverse the wires and try again.  You can always test for phase by putting on some music that has some bass in it and adjust the balance left to right.  If it sounds like you have more bass when you fade it over to one side, they are out of phase and you need to reverse the wires on one of the speakers.  If it has the same amount or more bass when it's set at center (both sides balanced evenly), then they are fine.