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Whacking the Blower Fan Motor

Hello - first time post here.
I was wondering if there may perhaps be a more conventional approach to getting the blower fan motor for the AC/Heat in my 1990 Mazda to work consistently - other than whacking it with my hand or foot? Is there an easy fix for this?

Thank you.


Replace the blower motor.



Gotta agree with Tester and the colder it gets now the worse it will be.

Yes, but if you can’t afford to do this job now, you might be able to buy some time.
With an old fan, the bearings are likely going. You might be able to get it to work for awhile if you can get some spray oil in there onto the bearings. This may, unfortunately,
stink up the car for awhile. You could try. However, if you are able to whack the blower fan motor, maybe it is located in a spot where you could get to it to replace it.

DC motors like that stop working for the most part b/c the bearings are getting a little stiff, or the brushes are wearing out, or the commutator contacts are oxidized. My guess for your motor is the problem is the latter, commutator oxidized. As long as the DC power input measures ok, pretty much you have to fix what’s broken to get it working consistently again. Auto-electric shops can fix all of those problems, but I’d guess the cost to fix a heater blower motor might be more than replacement blower would cost.

If you’re a scientific type you could try it yourself I suppose. There’s plenty of articles on the internet likely avaible via a Google search that will give you technical guidance on each of those repairs for DC electric motors. If the problem is an oxidized commutator, that can usually be fixed very easily with a little emory paper (a type of sandpaper) as long as you are able to take the motor apart and put it back together again. I mean in the same configuration w/no parts remaining in the box once the repair is completed* … lol . …

  • This reminds me of the Car Talk episode where a caller claims if you take a VW Beetle apart and put it back together enough times, you’ll eventually have two of them.

I have tried to keep a few heater fan and wiper motors running when replacements were not available and it wasn’t worth the effort in most cases. AC supply stores have a very light oil in a dispenser with a plastic hose to get into tight places for oiling electric motor oilite bearings and it sometimes gets the motor operating again but usually not for long. The fan motor must be removed to get at the fan end to oil it and it may be necessary to oil it every time you want to turn it on. Of course there may be leaves, etc., interfering with the fan and kicking the housing gets things stirred up. It may be worthwhile to remove the fan and clean the debris out of the housing and oil the bearing and hope for the best.

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