I have a 2001 Dodge Intrepsid ES, and have had a/c serviced and after a few days it would blow off the presure valve on compresser a couple of time for a second or two, but afterware it seems to work ok except for when going slow or stoped,.. and I noticed that my fans don't come on until the engine temp readhes about 1/3 the way on the gage. I am not sure but I thought that the fan would run fulltime when a/c was turned on, but this only run when needed for motor, then turns off. So I was wondering if this is why my a/c doesn't work well at slow speeds and when stoped, Also note, the when I am stop or going slow for a bit, I start hearing a air excaping sound coming from the air vents, but it is not an air leak, just a sound it makes when air start get warmer, then when I start moving again, it will slowly quit as air get colder.. and even if you speed up RPMs on motor, it doesn't help, car has to be moving before air get cool again. Any info on what switch or sencer I need to replace to fix this so fan will run when air is on, and what may need to be replaced for air to work right, would be appreciated...