# carrier central unit



## sergeC (Nov 7, 2007)

i have a carrier central air unit sitting by the side off the house and for some reason the fan is running when the thermostat controls are all on off position can anybody knows whats wrong whith my central air  ? ?


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## glennjanie (Nov 7, 2007)

Hello Serge:
It must be either a heat pump or a wire has shorted out. Turn the power off and open the top, trace the wires from the fan and feel for bare spots. If you find one simply fold the wire and put a yellow wire nut on it.
If the short doesn't show up in that compartment, open the inspection panel on the side; sometimes a contactor will be welded in the closed position (from lightning or whatever).
Please post back and let us know how it comes out for you.
Glenn


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## Kashka (Nov 7, 2007)

Does the fan ever shut off or is it running all the time? 

If it shuts off It may be a time delay relay in there that allows the fan to run for some time to remove any residual heat.

If it runs all the time then i would agree with glennjanie that there may be a short.


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## sergeC (Nov 8, 2007)

hey thanks but i check all the wires and i could no find any short or any damage to the wires . the led indication from error mode list on the diagram is off wich indicate hardware failure what next .
thank you for help guys .


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## Kashka (Nov 27, 2007)

Did you check the contactor. The only way the fan will run is if the contactor is energized. Something has to be keeping the contactor engaged. I would check the contactor to see if it is pulled in. it is possible that the contactor is bad.

Let me know wht you find.

Thanks


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## glennjanie (Nov 28, 2007)

Hey SergeC:
The contactor could be pulled in by a short in the control wiring also. However, if it is the contactor, the compressor should be running too. Carrier units are a real challenge because they have a circut board like a computer and quite often the only thing that works is to replace the whole circut board or bypass it if you are advanced in that kind of work.
Glenn


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