2000 grand caravan

I have a problem having the air on in my caravan it overheats only when ac is on no other time i replaced the thermostat and gasket but still have a prob open to any and all sugg.

with hood up vehicle in park and idiling (set emergency brake) turn on A/C go back under hood to see if radiator cooling fan comes on if not check fuses, if good suspect cooling fan controller..