I have 2 12inch subs and 1 600 watt amp running a 4 guage wire from the batter. Never had any problems! After I hooked up my APC and autometer guages which consist of APC voltmeter and autometer air/fuel C2 guage .

So I go driving and all of a sudden my system cuts out and head lights dim.
I alread had it checked and its not the alternator.

As far as how the guages are hook up, I have both the voltmeter and A/F guage running off the same power and the running off my dash lights. I have both grounds going into my car alarm ground.

 

try spearate grounds. common grounds can cause problems. make sure you ground to unpainted parts of the frame. do your lights only dim at high volumes when there is a lot of kick from the subs? you could need an alternator with higher amperage or maybe a cap. try the ground solution first though.

 

Your dash light wireing is probably only good for about 10 amps. I would use a new fuse direct to the battery for the power wire.

 

does the system come back on? could just be a fuse. god knows i've blown a number of fuses working on my car.