Heating, Air Conditioning, Fridge, HVAC/Thermostat


This past fall i purchased a new Thermostat (Honeywell RTH9580WF)

Since there was no C wire i connected the G wire at the board and thermostat. It worked perfect all winter but i tried to test my AC before it gets to hot out and the blower motor does not turn on.

The unit itself runs fine and the pipe going into the furnace is good and cold but the blower will not kick on.

Do i need the switch back the C/G wire and run a new one for the C so the G is still connected?

Hi Todd, The short answer is yes. If you move the green wire back to G terminals you should get the blower to work. Sounds like your blower is started by the furnace in heat mode. In cooling mode the stat starts the blower.

Did you check to see if there are any spare wires on the stat cable?

Hope this helps you out. JIM

Heating, Air Conditioning, Fridge, HVAC

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Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

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