when i turn on my ac, there's this weird noise coming from the cooling fans. it sounds like a plastic bag is stuck in there and its flapping around. when i turn off the ac, the fans stop and the sound stops too... has anyone else had this problem????

 

Check the fans to be certain there is no plastic bag in there, or:
Disconnect the connectors from the cooling fan and condenser fan motors.
Test each motor by connecting battery power to terminal 2 and ground to terminal 1.
If either motor fails to run or run smoothly, replace it.

 

there may be a plastic bag between the radiator and condensor. Happens a lot. take off the upper radiator shroud and look between...you may be able to pull it out.