I started out at the condensing unit. Everything looked fine but there was no call for cooling. Time to check out the controls...
The thermostat was calling for cooling. The relays, time clock, logic module and transformers didn't look out of the ordinary. I started tracing the wiring for the open circuit.
The problem turned out to be a defective condensate safety switch. These pumps have safety float switch that turns off the a/c to prevent flooding in case of pump failure. The pump worked fine so bypassed the switch until I could replace the condensate pump.
