I have a 2000 Chevy tracker 4 door 4 wheel drive automatic. Yesterday was the first time I've drove it since I bought it. Ran fine for 2 hours then I turned the air conditioning on to see if it worked. The air got cold then stopped completely. The car wouldn't speed up and began over heating. Turned the a/c off and pulled it over the heat gauge was all the way to the H in seconds. My father works on cars and changed the water pump/sensor and would not overheat until we drove it within minutes of driving it was too hot to run and the battery will not run anymore without being jumped. Can someone help the fans both work and runs perfectly fine until you start to drive. Does not over heat when revving the engine or on idle.

 

Did you check the thermostat? Might also have a partially clogged radiator. You can have it back flushed.