American Standard 1 1/2 tone heat pump, replaced the contact switch on the compressor unit. Replaced wires per pic I took. Turned the thermostat to heat. Increased the temp above the ambient room temp. the air handler powered on. Went outside to the compressor, it was not powered. I pushed in the contact switch, unit powered up. Release the button, no power. What else could it be?

Why did you change it in the first place? What was wrong?