It's always helpful to run a fused distro block....that way when you're wiring shit in the trunk, you can just pull the fuse for the piece you're working on rather than disconnecting the power......the baby jesus cries every time somebody disconnects the ground and has to reset all their HU settings //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
It's a lot harder to kill an amp than it is to kill a sub. From my experience, you either have to be a total bonehead while you're wiring it up, or run it at a super-low impednece or something else that gets it really hot....even then most amps have internal fuses and overheat protection that will keep you from killing it. Any install should have as many fuses as possible, especially if you're a noob.
Try this:
1 fuse 6" from the battery in the main power cable. This fuse should be the sum of all accessories running off this line (ie if you have an amp wiht 2 40a internal fuses, a crossover with a 10a internal fuse and a line driver with a 10a internal all running off your main line, this fuse would be a 100a because 40+40+10+10=100)
1 fuse behind the head unit in the remote line. Most HU's don't put out more than a half amp for remote, so usually a .5a fuse will work. If not, you'll just blow the fuse and have to replace it with a larger one.
1 fused distribution block with all your accessories running off it. again, put fuses in this block equal to the internal fuses on the equipment it's supplying power to (so if it has 2 30a fuses, put a 60a in there)
If you follow my advice and use common sense, you'll never hurt any of your equipment no matter how hard you try //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif