Re: blower motor on newr model

["Graydon D. Stuckey" <graydon@apollo.kettering.edu>]

On Sat, 3 Oct 1998, jimbo wrote:

> My 93 100CS blower make a whining noise, that comes and goes with AC or
> heat on.  Generally, the noise starts after blower is on for a while.  A
> road bump may start up or another bump may make it stop.  Putting brakes
> on (forward inertia) makes it worse.  Accelerating (backward inertia)
> generally makes it lessen.

Since this is exactly the thing I do in my real job, I suppose I should 
try to help.

> I though perhaps there was a leaf or some foreign material in the plenum

That's a reasonable starting point.

> touching squirrel cage, but I opened rubber part and stuck my hand in
> and couldn't feel anything.  Cage turns freely.  Even with the fan
> running and sticking my finger in (carefully) just touching the cage,
> doesn't result in anything.  I though putting a light load on it, noise
> would be evident, but it didn't.

OK, that's good trouble shooting too.  Exactly what I would have done.  
Well, almost - I would have immediately replaced the blower and sent it 
back to the manufacturer to report why we got this squealer.  :-)

> From what I read on digest, the bad bearing thing causes symptoms like
> no starting  or slow starting.  Mine isn't like that.  It's just a high

Correct, when the bearing gets really bad.

> pitched whine that comes and goes.  Sometimes, when it gets real
> annoying on a trip, my wife will turn off fan for a few seconds and turn
> it on.  This might work or not.  It's crazy because sometimes it doesn't
> make a noise for hours on  a trip, then it starts up.

That sounds like a dry bearing to me.  When the lubricant goes dry, but 
the bearing itself is still in decent shape, the armature can wobble in 
the bearings, causing the high pitched squeal sound.  Its like a wagon 
wheel on a tricycle.   If you spin it just right, it will spin cleanly 
without making any noise.  But if you spin it  alittl off axis, it will 
wobble, and slow down very fast.   The armature is the same way.

Drop a few drops of oil in the bearings, and the felt lube retainer 
around the bearings, and the noise will probably go away.   That fix may 
not last very long though if the bearings are already too far gone.

> Holland, MI

If you're ever in FLint, bring it around - I'll take a look at it.

Later,
Graydon D. Stuckey

"There's alot more to Jazz than just wrong notes"