York Thermostat Wiring : 2 / Check wiring between thermostat and sensor.. The existing trane thermostat wiring does not match up with the wiring of the honeywell. Incorrect wiring can damage the thermostat, transformer or blow a fuse. I have a old york heatpump with a honeywell q674l base with t874r thermostat. View and download york thermostat user's and service manual online. Add one to your home and do it in one day with this handy diy guide on wiring a thermostat from the home depot.
