3rd gen nest thermostat. Opened my sister and this yellow wire isn’t

Old Thermostat Wiring Color Code

Thermostat wiring wire heat color diagram guide air pump nest goodman colors honeywell code conditioner heater handler common wires carrier Thermostat wire color codes and conventions

3rd gen nest thermostat. opened my sister and this yellow wire isn’t Thermostat color heat wire codes wiring wires room old install thermostats 24v removing

Thermostat Wire Color Codes and conventions

Thermostat Wire Color Codes and conventions
Thermostat Wire Color Codes and conventions

3rd gen nest thermostat. Opened my sister and this yellow wire isn’t
3rd gen nest thermostat. Opened my sister and this yellow wire isn’t