weird problem
 

well i finally switched up my main power and ground wires to 4g. huge diffrence in voltage. she is running a 14.4 lowest, 16 @ idle. with a stock 60 amp alt. i did the big three in 2/0. so that may be a contributing factor. anyways. i was running 8g before. with a constant 13v. with the old wires i could turn it up till it distorted, on my HU is about 35 outa 40. now with the new wiring i can turn it up to about 28, and everything powers off and restarts, HU and all. never blown a fuse with this setup, so i dont know. could it be my ground? should i have multiple grounds? should i ground my cap ( ya ya ) to diffrent location as my amp? could this be a ground loop? this has never happened to me before, so im a bit at a loss here. any help would really be awsome.

Im not sure about the shutting off but 16v is kinda high at idle. Sounds like you don't have a ground screwed down tight or something.

the cap was adjusted to high maintaining 14.4v, but still have the same problem

Get a portable MP3 player plug it into the amp bypassing HU and see if it shuts off. It could be that there is a voltage drop at the HU that causes it to shut off. When you do this be sure to put a jump wire on the remote to the amp from the main power. This will eliminate the HU all together. You may have to run a thicker 12v+ wire from the battery to your HU like a 10-12gauge. Do the ground as well.

BTW if you are reading your voltage at the cap there may be a adjustment screw to adjust the LED output. You simply put a multi meter on the cap pos and neg and turn the screw till your output reads the same as your multi meter. 16V is out of wack for a stock electrical system. SO I believe your LED meter is not calibrated.

your voltage regulator has issues if your charging at 16 volts dude