Hello I have an old Concord a/c unit that was running fine than just shut off, I seem to not get power to circuit board so I checked transformer and the power side failed, changed transformer got power to board but unit would not start got an MAIN LIMIT SWITCH FAILURE CODE, Tapped on all the switches and the compresser, blower and unit started and worked fine for awile now it's back off and doing the same thing, Any ideas please.


Kris