My Amps run #4 cable from the capacitor to each Amp on both the positive and negative side. The capacitor is powered by a #0 wire from the battery. Using this set-up I have no issues even when running at night using the headlights and the volume above 20...Which it is a lot...The whole system is more powerful than most would like...Only down side is you have to Dynamat the crap out of everything to get really good sound...there's a point where it becomes a "must have"...
I had some grounding issues in the dash when everything was first built...turn up the volume and the oil pressure would drop and the temp gauge would rise...grounded those gauges back to the engine and it was corrected...
Alternator is a one wire Powermaster unit...I think 75 amp...