Defrost control board turns out side fan off during cool

by Hill
(Central Arkansas)

Model Carrier 25HBC536A300 S/N 2211E06528 While the heat pump is in cool cycle (running well) the indoor fan turns off and the compressor keeps running until the high pressure switch cuts it off. It has a new fan motor ,control board & start capacitor. Will the defrost thermostat cause this problem in cooling mode? I bypassed the fan relay on the control board and plugged it into the compressor relay & everything works great. But I will need defrost this winter.