need to check the fuses - i am at work and can't look up the WDS wiring diagrams... if you are good with those, you can look them up yourself, look for supply for amp, it will show which fuse is feeding the amp... unless somebody else will post the info meanwhile, i can only look it up once at home, which will be very late today...

ther is also a separate, 10A fuse in the radio harness itself that might be of interest, as that fuse is not lined up with the other fuses, and is not easily accessible...

was there any recent work done in the trunk? battery change? water in the side pockets?