Quick question on how thermostat relay wires work?

When you turn on the fan, does it just send 24 volts from the red wire to the green? And is that 24 volts constant the whole time? I have the fan on on the thermostat and i am testing the green wire at the fan base and there is not voltage coming through it.Quick question on how thermostat relay wires work?G is normally designated for the fan and yes there would be voltage as long as you have the the fan on switch on. Like Jim told you, to limited info to know for sure.Quick question on how thermostat relay wires work?It depends on how the system was designed and installed. Your question does not have enough information to diagnose the question over the net. Your best solution is to call a qualified professional electrician or to learn how to read the wiring diagram for your system.