hi i plan on running 1 1200 watt rms amplifier. what kind of electrical upgrades are nessasary to get the full power out of this amp and keep from dimming? also what size wiring kit dont plan on getting any bigger amp then this but you never know.
The reason your lights are dimming so much is you dont have enough alternator for the power your running. Part of that 90 amps is for your vehicles basic electrical needs.
Ok i really dont have money for an alternater at the moment. i heard something about the big three is really the only upgrade i would need with 1200rms, and a better wiring kit. what about a cap?
You can keep the gains down until you get the alt. A cap is not going to do you any good for this scenario save the money you would spend on one for the alternator. Read this for a more elaborate answer.