I have a Coleman Evcon furnace model DLAS075BDO (last digit could be a "D") which has had a finicky centrifugal switch for several years. Each new cold season, it wouldn't start and the error light would flash 3 times indicating it was stuck open.
When I tapped it, it would start up and everything would be fine as long as I used the furnace regularly. If it wasn't used for a few days, it would stick open again.
I finally decided to replace the whole unit (centrifugal switch and motor assembly) which I ordered through this site (mobilehomerepair.com).
The new unit appears to be doing the same thing, except it fails to start up every single time unless tapped, and the error light is flashing twice indicating the centrifugal switch is stuck "closed".
The voltage reads about 22 volts (my meter could be slightly off) at the circuit board, so I'm not sure what to check next.