Ahhh well you got my vote.

 

Upgrade your big 3 (alt to battery, engine to battery ground, battery to chassis ground, and you can add an engine to chassis ground as well if you want). Make sure your ground for the amp is in a good location.

I don't recommend a capacitor unless your lights only dim a tiny bit. Capacitors put more of a strain on your electrical system, but they will help smooth out the load a little bit.

If the upgraded wiring doesn't help, an upgraded alternator is best. Don't bother upgrading your battery unless you plan on running the system w/o the car running. In which case an Optima yellow top would be good.

 

k guys start by checking your ground...when an amp has a bad ground it tends to draw alot of current hints lights dimming...k then make sure its the proper size power and ground wire for your setup

 

Or the amp Is just drawing to much power for the alternator like everyone else said.....Alternator or a Max Cap will def do the trick or ya !

 

yes i know that but bad grounds can cause an over consumption of current due to lack of ground path

 

it probably has to do with your battery...so most likely you would need a capacitor since your battery isnt strong enuogh