Originally Posted by
TrojanHorse
Oddly, I have that exact same problem but I'm going to let somebody else look at it tomorrow. It's an old system, if they fail to show, I might do the hobo bypass rig you did.
. Meanwhile, my whole house fan is ALSO misbehaving so the house is unreasonably hot this year.
Ours is 20 years old, we replaced it shortly after we bought this house in 1999. The manual has a nice schematic so I was able to identify the fan power leads. The low speed fan only switch worked, so I pulled the wire off that tab and put the wire for the high speed AC fan feed on it, turned on the fan at the stat and it ran so I confirmed the fan itself is ok. Then just had to connect that high speed fan lead to a 120VAC hot lead with an old light switch, single gang box, some bits of wire and a crimp-on spade terminal. Whole unit is rated at 12 amps so I used 14ga wire, nothing is getting hot, smoking, sparking or melting, so all good!
Control board shipping was delayed, now supposed to be here tomorrow morning so the hack has been great. Happy wife, happy life, right?