Thread: Battery Volts fluctuating and now stalling

I have a 2004 Gtp CompG. I noticed the other night when I would slow down it had a squealing noise and my headlights would dim way down but my battery stayed at 14.60. It had rained that night so we decided the water must be getting on the belt making it slip. Took it out today and it ran just fine, no issue at all..Tonight was a whole different story! It was raining again and the squealing started but my battery would go from 14.60 down to 12.10 and than jump up again. Sometimes it would only be a matter of seconds other times it would take a few minutes. When the volts went back up the car would jerk/pull and keep going. the squealing only lasted for a few seconds at a time. Still thinking it had to do with the belt I wasn't worried until I turned it off started it up 15 minutes later and it was like it didn't want to take off.. I put it in park than drive and took off and it acted fine. drove a ways shut it off for about ten minutes started it back up and it ran rough!! sounded terrible! drove a few hundred feet and it stalled out. Waited started it again and when I took off got on it, no hesitation at all. It was back to running fine. drove about ten miles to where I was headed and shut it off.. Left several hours later and it started up fine, backed out of the driveway and went to take off and it dogged down went a few hundred feet and it stalled out. the battery went from 14.60 to 11.80.. Started it again and got on it right away, at first it hesitated a bit(choking out) and then it took right off. drove about 35 miles and it ran just fine. It seems like after it warms up it goes back to normal. I've had no problems getting it to start, no check engine lights or warning lights have came on at any point. I run premium fuel and full synthetic oil in it. My gas tank is almost full so I have no idea what's going on with it. I don't know much about cars and even less about this car. Please help!

2nd the pulley idea.

Next time it acts up when you start it pop the hood and take a look at the A/C compressor and see if it's turning. Seen this happen when the bearings start to go in them.

Thank you for the help everyone but I'm still having problems. I took my alternator off and had it tested...It worked just fine. So back to square one. I had a guy come out tonight and look at it. When you first start it, it doesn't want to stay running but after it warms up its fine. The guy was going to look into something and get back to me. Any ideas on what I should try next?

The check engine light is not on. I drove it to work today and it did the same thing, shutting off but after it warms up runs fine. In the afternoon I noticed that every time it shifts it holds back. You can feel the car pause but nothing else happens and it keeps going. It hasn't made a squealing sound in the past few days but it hasn't rained either. I had it looked at tonight after it got cold out and as soon as it started running funny he put his hands around my cold air intake cone. ( no idea what its called) and it revved up and ran fine. He checked the maf sensor and said it was clean. He was positive it wasn't a vacuum leak. I did leave one thing out and that was I filled my gas tank up 3 hours before all of this started to happen..not the lights but with the car running like crap. My brother put Cfoam in my tank the next day but the situation hasn't changed. I still have 1/2 a tank left in it. Should I go ahead and change the maf? on another note I don't think this has anything to do with the problem but he was telling me that I should use a certain type of spark plugs in this car. Any idea on what they would be? I've only owned this car for three months so its all pretty new to me. But I think its strange that since day one ive been getting around 17 mpg with it. I have a 01 chevy Silverado Z71 1500 ext. cab with a 5.3 v8 and I was getting 16 mpg with that.

Today it ran just fine! The only problem it has is that when it shifts its still pausing..