At 400w you should be fine with a stock alternator. If you ever decide to go any bigger, I'd suggest a 3G conversion. It's not NEEDED, but it sucks at night time to see your lights fade from bright to dull because of your subs hitting lolI have two 10's on a 400w amp. It's an old setup from one of my buddies. So far I don't have any problems with voltage drop.
I've actually been meaning to find someone with a system in a fox because not very many people in my area have fox bodies. What brand subs are they and are they in a ported or a sealed box? Once I get mine on the road I'm putting in 2 12" Rockford Fosgate Punch series subs in a massive ported box in my fox and I'm debating whether or not to use the 400w amp I have for them or step up to a 1000. I like bass. A lot lollol I think 400w is just fine for me, they hit pretty damn hard and I don't even have them turned up very far.
2G or 3G alternator?Those 2 wires are the old speaker wire when i first got my 90 it had 2 sets one was the old set and the other was one someone had ran threw the car which was a pain in the ass to figure out what went were. And im running a 1400 watt jl audio amp to a single alpin r series 10 that thing hits harder then my buddys 2 12s lol but everytime i turn on the lights my voltage meter gets dragged way the hell down even when i dont have the sub hitting and i just replaced the altenrnater i wonder what that could be.
There's your problem. In my Bronco I had two 12's powered by a 400 watt amp along with the two 15's powered by the 1000w amp. 1400 watts is a little too much for the 2G alternator to handle. Voltage drop was drastic when the subs hit and that was with no accessories on. Headlights, blower motor, and wipers along with a song with heavy bass? Ha, forget charging. Constant voltage drop.
There's your problem. In my Bronco I had two 12's powered by a 400 watt amp along with the two 15's powered by the 1000w amp. 1400 watts is a little too much for the 2G alternator to handle. Voltage drop was drastic when the subs hit and that was with no accessories on. Headlights, blower motor, and wipers along with a song with heavy bass? Ha, forget charging. Constant voltage drop.