I would like to connect booster fan to the blower motor in my furnace. The blower motor has 5 wires going to it:
And 4 others:
The booster fan is 120VAC and I wonder which wires is it best to connect to?
They all get voltage when the the blower turns on.
Should I use relay or direct connection will be better?
The furnace is Trane XR90.