Sorry for the long winded post, but here goes. I have a 2011 Escalade ESV. The front driver and passenger zones wont get hot, not matter what setting(defrost, vent, bottom). The rear heat is working fine! The coolant level is where it should be and both hoses going to and from the heater core are hot. I have not recently changed the thermostat or water pump so I dont think air in the line is an issue. Also it is not overheating. I checked the passenger blend door actuator by taking it off, then plugging it back in and changing the setting and was able to see the actuator move. I also checked the blend door to ensure it was able to move freely, which it did. The temperature of the air never gets ambient or even warm, its as if the ac is still running. Additionally I have put the ac in calibration mode twice now. This issue started Friday morning and on Saturday I tried to troubleshoot. After messing with it for two hours and getting no where I put it all back together. Hours later I took it for a drive and the heat started working out of the front vents. On Sunday morning it was working for a short drive, but when I drove back home it stopped working again. I went back to the passenger blend door actuator tonight and while it was running, I manually moved the blend door and left it running to see the vents would warm up, they did not.(I didnt try this on Saturday). While I was taking the kick plate off, I did notice cold water was dripping from some hole in the plastic housing. Something to note, two months ago while on a road trip I smelled something that smelled like electrical burning, found no smoke and no problems with the ac system at the time. Im at a loss. Is there a heat control valve for the front area? Could the Blower Motor Resistor be bad, even though the fans blow fine? Is there a there a thermostat or temp senor that could be causing this ?