The AC on my 2002 Grand Caravan Sport (3.3 Flex) works fine, except when the van has been sitting still at idle for a few minutes. After 5 minutes or so of idling, the outside temperature display on the overhead console starts to increase up to a max of 120 degrees, and the AC starts blowing hot air. Is there a fan relay or something, that would automatically turn the AC fan on when it reaches a specific temperature, and why would the outside temperature display increase?

 

Did you check the ambient temp sensor? You may have a problem with the sensor.

 

it was the ambient temp sensor. it was actually snapped off it's mounting point, and stuck under the radiator. I got a new one, remounted it, and all is good. thanks