I installed two amps a 4 channel for my speakers and a mono for my subs, do i need to run 4 gauge wire from the battery to the trunk to the power distributer or because i already have an 8 gauge installed for my mono amp and i want to know if i can just use that to power the both amps, also what number fuses do i need for the 8 gauge and if i need the 4 gauge what fuse do i use for that? thanks

 

Add up the RMS wattage on all of your amps. Then figure out roughly how long the wire needs to be to run from battery to distro block then go here > Canadian Car Audio - Recommended Power and Ground Cable Sizes Use the table at the top and find the gauge size you need. Then add up all the fuses in your amps and use the lower right chart to confirm the wire is big enough to handle the total current draw. Hope this helps, I am sure there are more experienced guys on here that can help a little more, but that is the way I would do it.
Nick

 

go here WIRE around the middle of the page you will find a simple but effective power/ground wire calculator("system power design assistant").. imput your sys info and click enter. it will give you minimal requirments for your system. keep in mind this is minimal. always go one wire size larger for head room (later upgrades).

gl

 

why skimp just use the 4 guage better safe then sorry. Besides if you upgrade your amps you won't have to change the wire again. 4 ga. isn't that expensive anyways

 

Here is a site with a wealth of information, including many, many install guides and wire / power calculators. Lots of ads too, but everybody has to eat.

the12volt's install bay - Mobile Electronics Forums