[k80b62b]

I have a 1999 Buick Regal and for the last few days the starter drags a little then starts, so I drove to work and turned it off and tried it and it clicked, turnrd the key off tried again and it dragged and started. I replaced the battery and it dragged then started so I thought maybe the new battery was not charged so I let it run for 50 min and then drove another 45 min in the mean time I had the old battery tested and it was fine and the parts owner thought when it gets hot then the starter is getting hot so when I got home and that when the car has been running almost 2 hours I turned it off and hit the key and it started right up. Then next morning it dragged and started so now I am lost. Also before I changed the battery the AC was blowing cold air and after changing the battery it blows only hot air. Any thoughts?