2002 Escalade. Sometimes, the A/C suddenly stops blowing ice cold air, and starts blowing slightly cool air. Its the same at both the front and rear vents. I put a thermometer in the drivers side vent to track actual temperature coming out of the vent. When it's working, it blows around 45 degree air. When it's "not" working, it blows 78 degree air. Outside temp is always hot when this happens, like 95-105 degrees. But, sometimes it works fine when it very hot outside. I tapped into the A/C compressor wire and ran a small indicator light into the vehicle. So, the light comes on whenever the compressor is running. The compressor DOES run, I can see the clutch engage, a noticeable load hits the engine and the condenser fan turns on. When the vent temp runs up to 78 degrees, the compressor IS running. To eliminate the possibility of a heater valve issue, here's what I did: I turned off the A/C and moved the temperature control knob to the hottest setting. The vent temp went to 150 degrees (hot!). Then, under the hood, I put clamps on the input AND return lines for the heater core. The vent temp almost immediately dropped to 90 degrees, which was the temperature in my garage at the time. Then I drove around for 2 days, same problem. Only slightly cool air on day 1 and icy cold air on day 2.
The vehicle has been to 2 separate shops. Both shops discharged the system, checked for leaks and recharged the system. There were no leaks and the system was not low on freon. Of course, it worked fine while they had the vehicle. Can anybody help. Please?
have the same problem?
Friday, August 30th, 2013 AT 8:24 PM