Heat/AC Blower motor won't shut off


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Old 06-12-07, 12:31 PM
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Post Heat/AC Blower motor won't shut off

We were told that it was the thermostat, so we replaced that. No good. All winter it was a problem. We had to manually flip the blower on when we needed heat in the house.

Now it's the same with the A/C. The unit outside kicks on and off like it should, but the blower inside keeps running 24/7.

We can't afford to hire a pro (hubby has been off work with cancer). Is there anyone that could help us out and tell us what to check?

Thank you,
Shirley
 
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Old 06-12-07, 03:40 PM
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Fan stays on

You can try disconnecting the wire connected to the "G" terminal at the furnace. If this works, you have a short in the thermostat wiring. If it does not, do you have a voltmeter & know how to use it?
 
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Old 06-12-07, 06:27 PM
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Yes... he has a volt meter, and does know how to use it.

We replaced the Limit Switch, also, after being told that that was the problem - but that didn't help, either.

Also, if the switch on the limit switch is on automatic, the fan won't run at all.
 
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Old 06-12-07, 06:30 PM
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P.s.

Also, the safety on the door does work. He has tested it and there is voltage going thru.
 
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Old 06-12-07, 07:20 PM
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Automatic??

"Also, if the switch on the limit switch is on automatic, the fan won't run at all."

Sorry, I don't know what you mean by the above statement. Is this a fan & limit switch with a white button you can push in to make the fan run?
 
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Old 06-12-07, 07:24 PM
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Yes, the white button.
 
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Old 06-12-07, 07:30 PM
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Fan/Limit

How many total wires going to the fan/limit? If 4 (two top & two bottom) did you break out the jumper between the lower two connection terminals?
 
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Old 06-12-07, 07:46 PM
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4 wires. He said he though he removed the jumper. Right now there is a piece of plastic between them. Does that get pulled out also?
 
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Old 06-12-07, 07:52 PM
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Ok... the jumper is definately removed.

Still not working right.
 
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Old 06-12-07, 08:13 PM
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Wiring Diagram?

Is there a wiring diagram on the furnace? If so, find the fan relay, remove it, & check continuity across the two terminals marked "coil". Does the fan relay make a click or snap when you turn the thermostat to "fan on" or when the thermostat calls for cooling? Note: White button must be pulled out when checking for the sound.
 
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Old 06-12-07, 08:38 PM
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There is a wiring diagram, and we located the the fan relay in the control box. We don't see anything marked COIL. Sending you a picture of the wiring diagram in Personal Message. Thanks.
 
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Old 06-12-07, 08:52 PM
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Evidently can't send attachments thru here so would it help if I sent you a copy of the wiring diagram and a picture via email?

Thanks so much for your help and time.
Shirley
 
 

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