ok so at night when i am driving and let off of the gas my lights dim very noticably
the battery should be fine i took it off of my old car and it has never died on me or had any problems

also when i have my music turned up loud the lights will dim when my bass hits i am running 320 RMS watts on my subs and 150 RMS on my speakers they put out 800 max watts(combined)

I am assuming i need a capacitor to stop the lights from dimming from the draw of the amps but how do i fix the lights dimming

Thanks for your help

 

could be your system...you should get a capacitor...but to check your alternator when the car is running just disconnect your negative battery cable..

 

yea im gonna get one eventually but the headlights dim even without music playing

 

could be both. get a multimeter and test your alternator, if that's good disconnect your amp and see if that changes

 

disconnected the amp and nothing changed
whats the power on the alternator supossed to be?

 

Is the dash battery/charge light ON?

Is the alternator belt tight?

The dimming of the lights sounds like a bad alternator. Nevertheless, start by cleaning and tightening the battery posts/connectors and the ground wire connection and then have the battery tested an auto parts store. Some stores will also test the alternator free of charge.

 

^the light is not on
i will do the rest and get back in the next few days
thanks

 

with your engine at fast idle put the multimeter on dc and put it on battery red red black black and 13.5 to 14.4 is good, anything above or below is bad, below is not charging your battery, above is overcharging and will kill your battery, if that shucks out good do what he said CLEAN all youre terminals, and id start making new grounds or taking them off and cleaning their contact with the body and if that don't work, call jesus

 

You have good advice here, although I think the order is reversed. First, clean and tighten the battery terminals and ground wire so that the voltage measurements that you recommend are more ensured to be meaningful.

 

yea you're right, lol after a long day of work and school maybe i should just go to bed...