hello I've got a problem with my 97 auto gt about 3 weeks
while I use electric powered(windows ac radio ....) sometimes my rpm and voltage decreases even sometimes its stop working too I've checked the alternator to service it works properly I changed my battery but my problem still continues any reason why this is happening? thank you all very much

 

ddddd.

 

Something on your ride is drawing too many amps and the alternator can't keep up. Sound system, accessory lights etc etc.

 

If you had your alternator and battery properly checked and they are fine there's another problem. If it happens with any of your accessories such as power windows, a/c or radio sounds like you have a ground problem. If your alternator is putting out it's rated amps there is nothing in your car that will draw that much unless you have a high amp sound system. I'd check all my grounds first and I mean all of them. Check a manual for your car and see where they all are.
If it only happens on one circuit (a/c on) then your problem is in that circuit only. Hope this helps...... pm if you have any more questions.
thx.