I have the Advanced Audio system & My rear speakers suddenly are barely working. The volume is down real low. The front speakers are working fine. I put the fader like 3 lines from the end of the rear speakers to even out the sound, but still doesn't sound right, like something is grounding out. I checked all the wires in the trunk, & everything looks alright. I'm thinking maybe the amp went out, but they are still working, just real low. Can the amp go out with the rear speakers still & have some sound comming out. does the amp only control the rears. Has anybody had this happen to them or have any idea what might be going on.

Thanks.