I already switched out a bad Capacitor but the Contactor will not pull in on its own when calling for cooling. The unit that freezes might have an issue with the defrost cycle/components. Just not sure how to diagnose. I have more experience with non-heat pump units.
Got Two carrier Heat pumps that need some diagnosing to correct Frosting issue and outside unit not turning on. Might need a new contactor or maybe something wrong with furnace sending signal to contactor. Basically, the downstairs unit works but freezes in the winter. Upstairs just needs a part...