I have a question about the wiring for defrost timers in general. from what I've gathered most of them have 4 terminals. 1 for a common feed, one going to the defrost heater, 1 monitors the compressor which sets the time, and the last one goes to the thermostat or compressor to shut power off during defrost cycles.

what I want to make sure of is that it doesn't require a ground or neutral contact. it seems to me it runs off of the power passing through the common wire and the feed to the feed to the thermostat and or the compressor turn on wire but I want to be sure before I decide on a place for this timer. I'm installing it in a fridge where the timer it had was in the icemaker and is now gone so I'll have to pick another location probably outside the fridge. any information would be apreciated. thanks.