Sometimes getting the full expected voltage reading on a circuit can be misinterpreted. Don’t assume it means the connections in the path are OK. Use the methods here to test for acceptable impedance in the circuit.
Below is a great post from HVAC-talk.com
The only 100% reliable method for checking safeties (and board outputs) is to use a low impedance meter (or low impedance setting on the meter) or use an actual load. Even a 24 volt test light works great.
With a typical digital high impedance meter, you can read full voltage when you have a high resistance contact or connection.
Take a relay or contactor and connect it to the chain of safeties. If it pulls in, you have a low impedance path that shows you that you can eliminate any worries about the switches in that chain.
Credit to user timebuilder
AOP Committee/Professional Member
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This is a composite image and not an actual dial. It shows a variety of functions found on multiple Fluke digital multimeter dials. No single model contains all these functions. On many models, some function icons are displayed in yellow. This indicates the digital multimeter’s yellow function button must be pressed to select those measurements.
ON/OFF switch
AUTO-V/LoZ: prevents readings due to ghost voltage; found on the Fluke 114
AC voltage/LoZ: uses low-input impedance
AC voltage with low-pass filter
VCHEKTM: permits simultaneous testing for voltage or continuity; found on the Fluke 113
AC voltage
AC millivolts
DC voltage
DC millivolts
Temperature
Continuity: when combined with sound button
Resistance
Capacitance
Diode test
AC, DC amps and milliamps
AC, DC microamps