I turn the heat on set 5 degree above the room temp. the thermalst. Try to kick but neither outside unit nor the blower running. I turn on the fan only the blower run, I replace the new contactor it not run, I try to push & hold the click the system run. Give me some idea, thank you!

No low voltage signal going to the contactor,, trace from hp ,all the way to wherever,, check for breaks,