[kjoyes]

Thanks for that very informative explaination. My take of what you just explained is that the car accessories put out about less than 80 amps. so if you add a upgraded alternator that put out 80amps at idle your lights won't dim.
but if you have a stock that puts 40amps at idle and you have all your interior lights and stuff on the alt will struggle at idle to supply the fuse box and your light will dim.

Q: if you add a sub or a amplifier with the stock alt. this will make the problem even worse than it allready is?
and if you have upgraded alt will you need a bigger amp megafuse?
I think i will go with a 100 amp mega fuse to be on the safe side. dont want to smoke my wiring harnass.