If its overheating then I would definitely have to agree with Josiah b/c when a/c is on your fan should be running and you should have lower operating temps but just to make sure you know our cars run very warm stock right? Normal operating temps are between like 160-210 so its normal for it to go above halfway on the guage. Most people just replace the stocker with a 180 t-stat and bada-bing all better