Ok here is my system rundown.

Kenwood KVT910DVD
2 Accele 5 inch Headrest Monitors
Kenwood DVD Changer
Kenwood KTCSR901 Sirius Tuner
Polk Momo 6.5 Components (fronts)
Polk EX3 6.5 Components (rears)
JBL BP600.1 (sub amp running at 2 ohms)
JBL P80.4 (4 channel amp)
2 Infinity 1230w Subwoofers (Ported box)
Monster Cable 1 Farad Capacitor
Optima Red Top Battery
1/0 AWG Monster Cable Power and Ground Wire going into the cap and 4 AWG wire going into the amps

I have a really serious problem with my lights dimming, I mean a real problem. It is bad. Now I have upgraded the main ground from the battery to the frame with some spare 1/0 and also a ground wire I found on the other side of the engine bay. What should I do? I am thinking of the batcap 300 or 400. will this help at all. Should I do the batcap and do all new ground points in the engine bay as well. I know I may not get rid of the light dimming completely but I want to help regulate my voltage. Right now it is constantly changing drastically and I am afraid of hurting my battery or alternator. Please help with any advice.

Thanks

Here is the site Batcap