Yes, but it's not the complete picture. As said in part, a thermistor used in MVAC that is mounted directly on the evaporator and has less resistance at higher temperatures, signals the PCM to engage the compressor as long as the temperature of the evaporator remains at ~33°F or higher. Conversely,...

The Old Air units I have installed (and that is several, including the Hurricane and more traditional styled under dash units) are not fixed thermostats, but variable. You may want to call them and ask directly. I believe they have both types available , however. I personally dislike the idea of mi...

Thanks very much, I will pick that book up. That explains why I haven't seen these thermostat switch units or probes in the OEM systems I've pulled apart. I would guess they have a thermistor in there somewhere, just without the obviousness of a capillary tube snaking out of the evaporator. It seems...

Hi I've been looking at a couple of universal aftermarket AC systems: Old Air Hurricane and Restomod Air Cyclone. Both of these are compact systems with expansion valves. I have noticed both also have thermostat switches. I am no AC mechanic, but I have pulled a few air boxes apart in my time. I've ...