overheating

Hey all, Im new to the forum and am hoping someone on here could help me pinpoint an issue going on with my 01' 2.2 Cavalier. The back story: Earlier this week the temp gauge was parked at 225ish. I topped the coolant off and it continued to overheat. I limped it over to my dads filling it...

When running w/ the air off, neither fans run, causing the motor to overheat. with the air on, both fans run, and the temp is normal. fuses is good, i have taken the car to 2 places, neither can find the problem. 1 place says he is studying the schematics, but no luck. i know the car has 2 temp...