Thermostat Wire Color Coding

Can't figure this 3 wire system out or find anything in postal about it Wires coding terminal wire screws identify terminals spruce thespruce Thermostat wiring wire heat color diagram pump air nest guide common goodman colors honeywell code labels heater aruf handler wires

Can't figure this 3 wire system out or find anything in postal about it

Thermostat honeywell wires t9 ifixit valkyrie Honeywell 6 wire thermostat wiring diagram Color-coding of electrical wires and terminal screws

Color-Coding of Electrical Wires and Terminal Screws

Can't figure this 3 wire system out or find anything in postal about it

Honeywell 6 Wire Thermostat Wiring Diagram - Database - Faceitsalon.com