Heating, Air Conditioning, Fridge, HVAC/Carrier unit


QUESTION: My cousin has a Carrier that the inside fan is very intermittent.  It will run for a few seconds then stop, then start again.  I jumpered the safety switch, but that isn't it.  I also checked the run capacitor, but no luck there either.  It does this whether calling for heat or cooling.  Is there a way I can jumper a connection at the furnace to get the fan running without going through the thermostat?  I can hear the contactor (on the control board) clicking during this time.

ANSWER: Hi Nathan, you could jumper R to G in the furnace and see if the blower runs. If it does the same thing, then it could be a bad motor or the relay on the control board is dropping out. Do you have a volt meter?


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QUESTION: I have a volt meter.

ANSWER: What is the model number on the furnace?

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QUESTION: Sorry it took so long getting back to you.  I jumpered R to G and the fan starts and runs for about 3 seconds, then stops, then it's all over again.  The model is 58STA045-12 and the serial number is 3202A28210.

Nathan, I think the next step would be to determine if it's the control board or the motor. On the board you will see terminals marked "HEAT" and "BLW". Put your meter leads on those. You might have to pull the connecter out a little to get to the metal. Restart the motor and see if you have voltage. If you 120 volts and then it goes to 0 volts then the board is bad. If the 120 volts stays on after the motor stops then the motor is bad.

let me know if you have any other questions.  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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