speaker help

So soon after I got my truck I replaced the 6 disc double din with a single din Kenwood stacked on top of a cobra cb... Since I have the monsoon system, I used the gmos-04 to hook up the new head unit. Now I did this without paying much attention to how the system was before the swap. I was messing with the fader settings in the new head unit and whenever I set it to the rear, I can hear the sub rumbling but there's no sound outta the rear door speakers. When the fader is centered, the front components work and the sub works but no rears. It's a basic head unit with nothing fancy so I don't think it's buried somewhere in the settings. Could it be something with the swap or is it just blown factory speakers? Is there a way to put a volt meter on the speaker wires to make sure they're getting juice? How much voltage shoud they read?

I think you have the wrong GMOS, I've been running the AXXESS GMOS-01 3 yearsnow. I also installed 2 Sound Ordnance B-8PT Single 8" Amplified Flatsub everything was working first time go on a Pioneer AVH-P4200 DVD Receiver. Just check if the GMOS you got will work with the HUMMER and then keep on with the trouble shooting.

I got the head unit and gmos-04 from crutchfield... I read somewhere that the -04 was to be used in the hummers with the monsoon systems.

Oh never mind, I have the base model. Sorry about that. OK where is your RCA cables running and power and remote wire? On my set up I have the power and remote is running along near the door and the RCA cable down the center never touching the power or remote wire. If these touch the power can bleed into the RCA cables distort and just make it a pain for you. When I went about my setup I removed everything and lay down the wires knowing of show they won't meet each other until the go into the amp.

Its been a while since I put the radio in. There's not an rca cable. There's a remote wire to the amp in the back. I also have a base model also but it has the monsoon sub and had the 6disc changer. O wanna pull the rear door panel off and check the speaker wires for voltage but I dunno if it works like that...

Pull out the head unit first and make sure the wires are still all together and hooked up the right way. If you could take a picture so we know how it looks in there.

The gmos was pretty straight forward. The new radio harness connected to one side. There were two connectors that came off the back of the factory radio and plug into the gmos... Not really a lot of room for error. I may plug the factory radio back in and see if they work. I think they're just blown.