It should not. Is it actually going into defrost?
That would work so long as you understand the fan will turn off any time there is an Aux heat call, and not just from the condenser (defrost board) either, but also from the thermostat too.I have the idea to add a normally closed relay inline with the fan motor and use the X2 and B wires from the defrost control board to open the relay when it calls for aux heat. I found a relay with the model number 90-380 that looks like it will work with the 220v 1.7 amp motor.
Will this idea work?
1 - The yellow PWM fan control wire was already disconnected. It was just going to a disconnected 6 pin connector.For the coil:
1-Disconnect the fan control, it's now useless. (if it's still there)
2-connect a wire from y to t1 on the defrost board.
3-connect a wire from t2 on the defrost board to the coil of the relay.
4-connect a wire from the other coil pin to c (b for this unit)