hi guys. well im running 2 JL 500.1 amps. i have 4 guage on the battery and i fuse near it. should the fuse be a 100 amp ? my alternatoe puts out 85 if that matters. if not, what size is safe? i mean i want something thats gonna work when its supposta, not just the biggest size. also i have the 4 guage running to my trunk and split off into 2 - 8 guage short pieces running to my amps from a distribution box. now do i have to run another fuse on each piece of 8 guage wire when it comes out of the distribution block, and if so, what size? 50? 60? other? thx!!

The fuse on your batt should be no bigger then one and a half the size of the fuse on the amp. The most important fuse is the batt fuse. You don't have to run any by the amp, but it doesn't hurt. The fuse by the amp should not exceed the amperage of the fuse on the amp.

the fuse by the battery is more for short circuit protection than for protecting your equipment.

Personally, I prefer to fuse everything individually, usualy for a 500 RMS, D class amp, I'd put in a 60 amp fuse, at the battery a 200, or a 150 would be fine.

^^^i agree

what about a 100amp at the battery? is that too small?
also, in JL manual, it says you dont have to fuse it near the amp. what do you guys think? i dont even see a fuse on the JL. is it inside??

The fuze at the batt is to protect you car from burning if the power wire between it and the amp shorts to ground. That's it, that all. I maybe went a lil' over board but I put 1[80 amp] at each end of the 18 ft run of 4 ga wire that goes from front to back in my van. It is to protect from either set of batts shorting out and taking my ride with 'em. The fuse on the amp is rated at 40 amps. Overkill, maybe.

Your amp has an internal circuit breaker then, so your manual should tell you the current consumption. Atleast match your batt fuse to your amp fuse (circuit breaker). And no, a fuse is not needed at the amp.

the amp has no internal circuit breaker
i personally would fuse it
it could reduce the amount of catastrophic failure in the amp