I am currently using a Carrier/Totaline P3741900.
This installation has individual Amana non-heatpump compressors, and the second compressor never starts. It is in Houston, so it gets hot enough. The debris and spiderwebs confirm it does not come on. There is a separate toggle switch in a wall plate for selecting the primary compressor, and this allows me to confirm either unit will work.
Totaline will not confirm if this thermostat is correct, so I'm looking for a replacement for the Totaline unit.