I'm a bit stumped. You turn central AC on and it works OK the whole cycle, but when it cycles off and back on again, only warm humid air comes from registers forever. Condenser fan works but compressor is not running. Then I turn the system off again, restart and it works great but only for one cycle. It has been doing it for a second day and it's too dark to troubleshoot after work. Could low refrigerant do it?. I had a slow leak many years ago and fixed it, but don't remember doing the same thing, just weak cooling then. This is old unit with no fancy controls, but there is a control board that shows OK light on. Contactor and caps look OK and were replaced in the last 1-2 years. Starting relay replaced this spring. I guess it could be that. Thanks! PS: there is no need for AC this time of year, but this year is clearly not normal.