A malfunctioning temperature sensor will affect how much refrigerant is allowed into the evaporator. If too little enters, there will be insufficient cooling. Too much and the evaporator will go below 32 degrees at which point the condensation will freeze and block air flow. You would experience great cooling for a few minutes, then a loss of air flow until the ice melted.
Now, that's how MOST cars work. In yours, they might be using the sensor to cycle the compressor on and off via a computer. Lord knows every former simple, trouble-free system on today's cars has a miserable computer added to it. I'm not aware of any common, or pattern failures with the sensor but that doesn't mean it isn't possible.
Just out of curiosity, have you noticed if the electric radiator fan runs at times? If it does not run in slow traffic after the engine is warmed up, that could be related to the compressor not turning on.
Sunday, May 23rd, 2010 AT 3:28 PM