Deodiaus wrote:
Any guesses as to what is wrong with the winding?
Someone suggested looking at the bearings. What do I look for,
excessive wear?

Well it's possible that this is still the original problem and the
capacitor was not bad to begin with.

The symptoms point to something in one of the two winding circuits.
There are two separate windings in a single phase induction motor. In
many motors one of the windings is only energized during starting and
then turned off by a centrifugal switch. But this thread has been
talking about capacitive run type (and that's common for blower motors)
so we can ignore problems with the switch.

If the two windings are energized from the same power source without any
capacitor at all, then no torque is developed and the motor sits and
hums. So one thing is it may be wired up wrong. Recheck your work
against the circuit diagram (often inside the panel or in a manual).

If the bearings or blower are seized up, the motor can't develop enough
torque to start spinning. Or you may get it started but the load is so
great that it overheats and shuts down. I think you mentioned it ran
for a while one time? When everything is turned off, you should be able
to easily turn the thing by hand, blower and all.

If one of the two windings has developed an open, then the other winding
alone can't develop torque to start and it will just hum. This *may* be
just an open in a connecting wire and would be easy to fix. But if it's
down inside the winding, rewinding a motor is quite a task and often not
worth the effort.

If your handy with an ohm-meter you can check for opens easy enough.
Just lift the leads and read between them. Be sure to turn off the
power though, ohm-meters tend to smoke when connected to live AC power.

daestrom