Duo Therm Heat Pump weirded out

I will definitely repost if any further problem happens. And I trust that Doug knows what he's talking about as well, as he's helped me in the past as well. Right before resetting, I did turn the circuit breaker back on and the compressor did start back up with the thermostat on off. But resetting did get everything working. Do you know why a low 12v voltage would cause the relay to stick? I have two ACs but only one is hooked up to the CCC thermostat. Do I need to change thermostats? I thought I'd done whatever was necessary to get everything running right when I bought the new heat pump a year and a half ago.