On Mar 18, 9:42 am, Ken Knecht wrote:
I put a new two-speed blower motor in my evaporative cooler yesterday.
The motor makes a pretty loud buzzing/humming noise. It does it with belt
off so it's the motor, not the blower. It's not the water pump. Checked
current draw with clamp-on meter and it's slightly (0.1 A or so) below or
equal to rated current marked on motor with the belt on. It's louder on
low speed - maybe because blower is quieter?). Other than the noise it
seems to work ok. I ran it for about 9 hours yesterday at low speed
(which I normally use) with no problems.

Just ignore the noise? I can live with it if it isn't trying to tell me
it's in trouble.

Any kind of noise means trouble. No motor last forever and your will
not either. So long as it's running and the noise doesn't bother you
then fine. When it starts shaking or vibrating then the end is near.
Small motors like that aren't usually repaired but they can be.

Sometimes you can blow the dust out and oil the motor. Small motors
like that are sometimes have a place that says "oil". It may be
possible to have it repaired if you are determined.

Why not got ahead and buy a replacement? Then you can have the old
motor looked at with the minimum downtime. Worst case: old motor not
worth repairing but is still a good backup. In the meantime you have
a quiet smooth running motor.