Just finished the heater blower motor/resistor swap. Unfortunately, I realized once it was buttoned up that the new motor vibrates like crazy, I can feel and hear it through the dash. What can I do now short of pulling everything apart again (8 hours of my life, gone...)

Prior to install I bench tested the motor and it sounded "normal". The box it cam in was torn up by the unprotected shafts, so I even inspected them for runout, but they looked fine. After installing fans on shafts, I made sure the spun freely. I guess I should have powered up the motor again at that point.

What could I have done wrong on install? If I dig in part way, can the fans need to be balanced somehow?

Peter P.
Portland, OR
'88 245

How bad does it vibrate?
I have seen little metal clips used to balance the fan blades.
Is it possible that a screw is not tight somewhere in the system?
When working with the three mounting screws for the fan motor it is poss.to push too hard on the screw prior to turning it,thus pushing out the metal screw race on the back side especially common with the screw that holds the resister (think back,did every screw seem to get good purchase?)

Yes, the three screws securing the motor were good and tight.

I don't recall seeing any clips on the fan blades. However, I did see a radial black sharpie mark on the outside of each blade (from center to OD). I made an attempt to allign the right and left blades in the same orientation. Unfortunately, I didn't notice the marks before removing them. This is my one hope to just dig back into the passenger side and start rotating that blade and hope it stops. I could also add weights (at least to that side).

Frankly this doesn't sound a likely scenario, or every brickboarder would have a balancing FAQ.

Peter P.
Portland, OR
'88 245

Hi Peter,

As you might imagine, I've been monitoring most blower motor topics here for a while now, and have never come across a similar report. Also, clips haven't been mentioned, except maybe on ceiling fans and HVAC blower squirrel cages.

Could imagine the impellers took some damage rubbing, before the replacement -- mine did -- but I think the whittling done was done symmetrically, with no ill result.

If I was in your place, I would "chainsaw" a disc out of each of the plenum sides at the hub (I'm thinking I would use a drywall cutter in the Dremel tool) from where I could at least experiment with the impeller balance. Looks like there's six options on each side. By removing the clip I could tell immediately if the motor shaft got bent in transit, just by running the thing for a moment with no coupling to the impeller.


--
Art Benstein near Baltimore

Do infants enjoy infancy as much as adults enjoy adultery?