AIR CONDITIONING ONLY COOLS FOR ABOUT 10 MINUTES UPON STARTING
1999 GMC Jimmy
August, 30, 2012 AT 8:10 PM
1999 GMC Jimmy LT V6 4.3L Vortec with 70,000 Miles 2 door 2WD. A/C works fine for about 10 minutes or so, then starts blowing ambient temperature air. If I turn it off and let it set for awhile (ie. 1 hour) and start up it, it will blow cold air again for about 10 minutes then starts blowing ambient temp air again. This happens every time I drive it. I have to add 1-2 cans of coolant every summer, but this problem only started a couple months ago. Is there some type of thermostat somewhere that is going bad? Thanks.
Yes, as I mentioned originally, I can let it set for a bit, then start driving again and it will blow cold for about 10 minutes, then will gradually over a few seconds just blow ambient temperature air. The blower continues to work fine. About the shortest period I've tried to let it set turned off before driving again is about 1 1/2 hours and it did the same thing after about 10 minutes.
August, 30, 2012 AT 8:44 PM
Sounds like the engine is getting too warm causing the pressures to become to high and cycle the compressor off.