my ac started blowing warm air the other day. i went to the parts store and got a can of coolant with the gauge on it. i put the guage on it and it read 45 the can said for an air temp of 90 it should be between 45 and 55. so i added a little to 50 and it was blowing cold again but after a short drive it started to blow warm again. the problem is while driving it will blow cold for a couple minutes and start blowing warm again then after a couple minutes more it will blow cold again. while driving it will keep doing this from cold to warm. does anyone have any idear what could be causing this?

 

check your pressure switches. make sure your fan is kicking on to keep the pressures down.

the ol can method of refilling isnt the best but works. Find a shop that does free A/C inspections. They can hook it up and check the hi side and lo side pressure. recharge and add some dye to look for leaks.

Sounds like you could just be a little low of freon.