Tried to run AC for the first time this season (Furnace works fine).
After looking around, the transformer was definitely burnt.
Bought a new one, swapped it out (after carefully re-connecting the proper wires), and the AC worked.
About a day later, transformer burned out again.
Bought a new one, buddy suggested I install fuses between transformer and the circuit board (Heatcraft 40403001 Cat 70K98). Sure enough, as soon as the compressor is to turn on, the fuse blows. Tried 2 amp, 3 amp, 5 amp, then 30 amp! Finally didn't blow at 30 amps, but transformer got hot.

After probing around other message boards, it appears the A/C relay is faulty, and drawing too much current. Does this make sense?

So... Where does one purchase a new main board?

OK, so I found replacement boards online, but the are $188!
Curiously they are the same at 4 different sites.
Do I need to know someone to get a wholesale price?

http://americanhvacparts.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=CIB9120C2028 &Category_Code=

OK, so I found replacement boards online, but the are $188!
Curiously they are the same at 4 different sites.
Do I need to know someone to get a wholesale price?

http://americanhvacparts.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=CIB9120C2028 &Category_Code=