Wiring sticky wrong?
 

Everywhere I see that the RF door speaker on a 2002 blazer (Xtreme) is dark green neg, light green pos. But mine are light blue and dark blue.

These are the correct colors for the RR speaker, not the RF. How can I figure which is pos, which is neg? I tried touching the connectors to the pos on the battery but both colors give 12 volts with the car turned off (6 volts radio on), giving the appearance that both are grounds.

I just opened the other side. The LF speaker wires are yellow and brown, the "book" colors for the LR speaker. Ideas for what's happening or how to wire my new spade-terminal speakers??

https://cimg0.ibsrv.net/gimg/blazerf...1f3f3fc0fb.jpg
RF speaker, which is +/-?

IDK enough about electricity but speculating... Is it possible there is no ground wire, the power just runs in and out of the front speaker and moves on to the rear speaker and it gets grounded there? In which case it doesn't matter how I wire the new speakers. Or does each speaker need it's own ground?

Light blue is the - darker is the +

It's not really a "ground" per say since speakers use alternating current as apposed to a 12+ and ground signal. The + and - designation just makes sure the speaker polarity is hooked up right so it's in the correct phase.

If it's hooked up wrong it won't harm anything (in the case of non-amplified basic door speakers like in this situation), there just might be some sound degradation since the speaker will out of "sync" with the other speakers, but honestly the average driver would never notice it...

Thanks Blazn, just in time.

Schematics are attached:

As Blazen_Red said, Light blue is the - darker blue is the +

On a 2002 Blazer 4x4 what speaker the colors are used on may depend on 2dr vs 4dr and what radio options, but whenever you have dk blue/lt blue to a speaker:
Light blue is the -
Dark blue is the +

Ouch! I'm going to go out on a limb and say that you shouldn't have done that. Hope your radio is OK. What do you mean by "give 12 volts"

After cutting the speaker free, I ran a wire from the +battery to each speaker wire in the passenger side door, trying to find out which one was the ground. Multi meter gave 12v DC, radio off. Aftermarket budget radio seems to be okay.
I did notice though that the rear speaker driver side does not work, maybe never has. What would be a test to see if it is the wiring, the radio or the speaker that has failed?

So your multimeter was on Volts setting, and was in between the wire from the battery (12V) and the speaker wire, correct? That's what saved your radio. Glad you didn't let all the smoke out of it!

If you put your voltmeter across the two speaker wires, you should be able to read some sort of voltage. But most people would just hook up one of your old speakers (one that you know works) to the speaker wires for a test. Doesn't have to be mounted.

Good call. I had a leftover speaker from the fronts and used it to good effect to test the sound-less left rear.