As relates to the ACC, it had no reliable control over the heat or AC. Different button-pushing sequences would sometimes get the desired heat or
AC, sometimes not. Tapping on the front of the control panel would sometimes start the heat. Defrost would sometimes have heat, sometimes it would have heat when turned on, then cool off as air went over the heater heat coils. (Mono-valve rubber is torn, needs rebuild as well. Most of the things I've read that have been diagnosed as a bad ACC it's been doing.

thanks
Bruce