Why would a switch read 0 volts when the light is turned on and 120 volts when the light is turned off ?
I am considering installing a zwave dimmer on a ceiling light in my extra bedroom. First I opened the box and tested the wiring. But my results have me stumped and thinking the switch will not work.
The case is when the switch is turned On, there is no power going through the switch. Reading with a volt meter. Seen here
When I turn the light Off the switch does have power flowing. Seen here.
This is confusing to me and has me wondering how this light is wired.
NOTE: I found a similar situation with a three way switch, when the switch is on, zero power any wire on the two switches, when the switch is off there is power flowing to one switch or the other. I chalked that one up to three way wiring I didn’t understand but this one is a single switch light.