Callback: The Low Pressure Switch That Didn't Make Sense

Customer called back after another technician had already been out. At first glance, it looked like a bad low pressure switch. I had 24V entering the switch and 0V leaving it. Pretty straightforward, right? Not so fast. When I checked continuity, the switch tested closed. Voltage and resistance were telling two completely different stories. This one turned into an interesting diagnostic challenge and a good reminder that you can’t always rely on a single test. Have you ever seen a pressure switch act like this? I also rant a little bit at the end complaining about manufactures #HVAC #HVACTech #Troubleshooting #AirConditioning #ServiceCall #HVACLife #LowPressureSwitch #JustInTimeHVAC