All tstat wire condenser and A/H were loose at wire nuts and a few popped out fixed wires and put new wire caps on found that 3 amp fuse and transformer were shot. Replaced 3 amp fuse and transformer tstat was turning on until stat was sending 24 volts to condenser unplugged defrost control board on condenser no further issue system is down and needs defrost control board. Customer will pay diagnostic when unit is up and running