SAIL SWITCH VOLTAGE CHECK
Hoping for help on troubleshooting a Furnace Sail Switch. Furnace was intermittently failing and now progressively worse. Blower would come on and after about 30 seconds would shut off - no audible at...
Forum Discussion
Checking the switch with the voltage setting on a digital multimeter with nothing else connected (other than the 12V supply) is tricky because the multimeter has a high impedance input, and any stray voltage, capacitance, etc. can cause misleading readings. More useful is to check the switch with the resistance setting, with no battery or power supply attached. It should read an open circuit (i.e. infinite resistance) in one setting and a short circuit (a fraction of an ohm reading, usually) in the other setting.
