JaxJags88GT

my idle is around 800, and when i turn the a/c fan on and the electric radiator fan comes on with the lights and stereo on, the car wants to die out. of course it's faily ok when the rpm's get up but dont want battery deing problems .i know it's lagging on juice, i talked to a couple guys about a "overdrive" pulley for the alternator, i have the underdrive pulley's on, but the stock alternator pulley, with a 130 amp alternator, but seems since the electric radiator fan i put on, it's not keeping up. is it worth 50 bucks for the aluminum overdrive pulley? supposed to keep the amperage up while your idling. seems that would work great for what i need, but does it defeat the purpose of the underrive pulleys and anyone have one on and is it working.