Where is the señor that shuts off the heater in the carrier weather maker 8000

Do you mean sensor?

The thermostat is the main control for off/on. The temperature setting must be correct, so that's where you start. Are you sure its the furnace/AC(?), or just the fan which typically is set for auto or manual?

Back to you to clarify your issue further. maybe this manual will help

https://www.manualslib.com/manual/25588/Carrier-Weathermaker-8000-58wav.html