Gene,

Depends, on if the defrost thermostat is closed and feeding voltage to the heater or not.

But, in reality only one (either end) of the heater is attached to the thermostat, and the other end is attached to the neutral side of the circuit, for the voltage to flow through the circuit.

I take for granted you're replacing the heater assembly, make sure the unit is unplugged, and switch the wires to the same terminals on the new heater, and you'll be fine.

Good Luck,

:) :) :)