i have 1 12" W7 with a Jl 500/1 amp.
4 gauge power wire, with a 60a fuse
8 gauge ground for the amp.

the lights dim when the volume is up really high...

stock alternator, stock ground wires...

will changing the ground wires take care of the problem? thanks

 

The amp ground needs to be the same gauge as the power lead to start with, [keep ground lead as short as possible] you should also add a 4ga ground from batt. to chassis.

Where have you got the amp grounded?

What type of fuse are you using on the amps power lead? 94

 

Civics have terrible electrical systems. i'd do the big 3 and run 0 gauge from the battery to the distro then 2 gauge from the distro to the amp.

 

and get a cap

 

First off hows your battery,power and ground cables,alternator?start by fixing the cheaper stuff and work your way to the expensive stuff(.i.e upgrade the power and ground cables along with the starter,fuse box,motor and trans cables then upgrade the battery(interstate or optima)then upgrade the alternator then add a cap)

 

There is no need to use anything bigger then 4ga power cable for a JL Audio 500/1, "0 gauge" is way overkill and adding a "distro", [distrobution block] would only add unwanted connections.

I agree with ekbublboy check and make sure the stock electrical/charging system is good first. 94