I had to drive home yesterday in the rain and with my wipers,lights,radio,and AC on my voltage was dropping to the middle of the yellow area. However when I turn the AC off it goes back up slightly to the beginning of the yellow area.Is this anything to be concerned with? because it scares me sometimes, thinking that Im going to stall, or something. I also noticed that my battery is not the correct one I need, because its only like 600CCA, but this sounds more like an altenator problem to me.

 

Try cleaning the ground lug on the pass. side of the strut tower. It has three major negative cables (black) running to it. Remove it and clean it thoroughly until the metal is clean and reassemble.

 

If it just happens in the rain your belt might be slipping. My car does that every morning when I drive through the water puddle in the parking lot of my apartment.

 

check your connections. get your battery tested. if your battery is good, check the output of your alternator.