FWIW, I live in the far SW corner of Arizona.

Probably lots more than you really cared to know.

The cooler makes noise when running. A sort of loud
"humming". It's not the water pump. A few days ago I tried
changing the blower belt to a new one. The noise
immediately went away - for several days. Unfortunately,
it is gradually returning. To me this indicates the motor
and blower bearings are ok?

The cooler runs fairly quietly when first turned on, then
gets gradually noisier as the day wears on. I generally
turn it on about 10 AM and off about 10 PM.

I have a new blower pulley but am reluctant to change it.
The blower shaft is hollow and I'm afraid if I use a
puller I'll crush the end. The pulley is very firmly
attached to the shaft because of the wet environment in
the cooler. Lots of WD 40 for a few days preceding an
attempt?

The motor pulley is an adjustable one, very handy for
setting the belt tension. Could this be the problem?

The blower pulley is the original and has not caused any
problems in the several years I've had the cooler. The
motor failed and was replaced with a new motor and pulley
at the beginning of this cooling season, probably around
April. I've used other 'identical' pulleys on motors in
the past with no noise. I don't recall that the noise
started soon after I replaced the motor, but my memory at
age 73 is not the most reliable.

I could dismount the motor and replace the motor pulley
with a new adjustable one but at my age and in the early
morning heat - 80+ - that is a job I'd rather not tackle.
I could live with the noise the rest of the year and
replace the motor pulley and belt next Spring when I prep
the cooler for another year. The cooler will be probably
used until well into October.

I keep the blower bearings lubricated.

Suggestions?

TIA




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