I have an older Bryant gas furnace and a Lennox central AC unit and have an issue where the furnace or AC will start up and run normally for anywhere from 20 minutes to several hours and then the 3 amp fuse will blow. I originally suspected a bad relay on the board, so I installed a new control board and was very careful with the wiring. I also tested the tstat wiring and transformer and everything checked out fine. When I was using the furnace, the inducer came on and the heat cycle worked perfectly, but after the blower came on, the fuse would blow...again at unpredictable intervals. The same thing is happening now with the AC, so I am starting to suspect something with the blower motor. Is it possible that bad windings in the motor could be causing a short that is blowing the fuse? Any suggestions would be greatly appreciated. This has been beyond frustrating!
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