Do you have a stereo system blackened? Are you running mainly at night or during the day?
I agree with both though. Blackened is right something is not doing its job all the way unless you are trying to run something like a big stereo that draws a ton of power.
Also I would always recommend running a 3g alt. There is a reason it went standard affair on 94+ mustangs. The stock one is wayyyyy too weak. About as adequate as stock brakes.
Most of the larger auto parts stores like AutoZone, Advanced Auto Parts, etc will check your battery and alternator in the car for free. Do that first and fix any battery/wiring issues before considering a 3G alternator swap.
thanx.. well my battery is kinda old. but yea ill look into the 3g...any idea how much it is? and yea when i turn my lights on at night it dies quick. but will see. im gettuin a new battery today
3Gs are pretty cheap on eBay. Should be able to get one for $80 shipped. I got mine for $50 shipped and I think Doc just scored one for $60 shipped. Just hunt around on teh bay