OK Testing done. BTW I started checking the forum for other problems like mine and I couldn't help but notice Majestic_roll in England and his problem. The situation he was describing sounds alot like the problem I am experiencing. Anyway I drove to a parking lot and did the testing. First I could not turn the system up too loud before one of the subs sounded like it was "bottoming out." Really don't understand since the gain on all 4 channels is set low, REALLY LOW. I can't really turn the gain or the system up to far before the music cuts in, cuts out and then finally goes away. BTW, I don't know if this is any help but I noticed that once I plug the RCA plugs into the amp at a time for all for channels, the green power light on the amp starts to glow dimmer and dimmer. And when I plug channels 3-4, sub channels, the light pulsates with the bass, kinda like what other people get with there headlights. And then sometimes the system is on H/U, Eq and then nothing. The green power indicator is not lit. Well enough of that here go the results.
test the battery posts=14.22
clamps=14.22
carbody/chassis ground/battery pole=14.22
wire just out of the battery clamp=14.23
wire just at any fuse block=14.23
at the amp=13.92
across amps terminal=13.75
BTW you will notice that I did not do the test before the fuse, after the fuse and just past the block. When you said any fuse block I used the one under the hood and so I did not know what I would have been probing before, after and just past. Sorry. I hope this helps.