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Discussion Starter #1 (Edited)
Blower motor upgrade


Thought this might help out some folks struggling with the factory Behr blower motor.
I decided to replace the motor and found that the VDO PM3340 is a better option priced at $35 rather than the factory replacement priced at $250.
The factory Behr motor has a poor design with the weak tension fingers holding down the brushes. If you'd like to replace it with a better motor here's the steps involved:


Disassemble the Behr motor by removing the housing and removing the squirrel cage. Applying heat to the end of the shaft will soften the press fit on the cage. Next, you'll need to modify the squirrel cage by shortening the center bushing to accommodate the shorter shaft of the VDO motor.


The VDO motor has the same 8mm shaft with 5mm threads on the end and the cage is held in place by a lock washer and nut.


Cut the Behr motor housing in half and remove all the material until you have roughly .250” vertical material left on the flange. Use a Dremel with a grinding stone.



Now, on the VDO replacement motor cut the mounting flange allowing about .750” all the way around for mounting to the modified Behr motor flange. This type of mount will enable you to install the blower assembly the same way as the original design.



When assembling the modified Behr squirrel cage you'll need to shorten the ears on the square cage support washer that comes with the VDO motor to about half of what they are, then flip it over using it as a stop for the cage. The nut will torque the cage to the shaft.


Lastly, you'll need to fill the gap between the new motor flange and the Behr motor flange to seal off the air flow. Weatherstripping works well. I also used a small piece of weatherstripping to plug the return air port that's located on the car.


The VDO PM3340 is a direct replacement for a 2000 Chevrolet Malibu if you'd like to order it from your local parts store.

I hope the photo links work...,

https://www.dropbox.com/s/hgzr2m3v3gdn34s/Smart_squirrel_cage_aftermod.jpg
https://www.dropbox.com/s/rr5gwldch2fx4ld/Smart_housing_aftermod.jpg
https://www.dropbox.com/s/m2qkcjrirumyq8v/VDO_motor_flange_aftermod.jpg
https://www.dropbox.com/s/nm6fruswcq65qj9/VDO_blower_motor_premod.jpg
https://www.dropbox.com/s/5rnymlxq2tcapz4/Smart_blower_conversion.jpg
 

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Good job, but I can imagine the puzzled techs at MB when this smartie is sold off and the new owner goes to the dealership for repairs :)
 

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Discussion Starter #9
Thanks everyone... This is a great forum, lots of good discussions.

wahi..., yeah, my intention was to upgrade the blower without changing the stock design. If you want to revert back to the original blower, just purchase and replace. I even left the stock wiring and connector intact; kind of a pet peeve of mind, I hate to see butchered wire harnesses. :eek:
 

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I posted the original how-to for cleaning the OE blower motor. I may just have to give this a try. I figured there was something out there that would work, just never spent the time investigating. $35 and a little bit of time is WAY better than the $280 the dealerships want....


Great job!!!!:thanks_smile:
 

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Well I've personally witnessed blower motor defects basically disappear after the 2010's. Somewhere down the line the manufacturer makes tweaks to lessen the percentages of failures. I believe there are far less defective blowers and the manufacturing of them improved somewhere during the supply cycle.

Some folks are going to have the blowers a little more prone to failure, some are going to have the slightly improved ones.
 

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Well I've personally witnessed blower motor defects basically disappear after the 2010's. Somewhere down the line the manufacturer makes tweaks to lessen the percentages of failures. I believe there are far less defective blowers and the manufacturing of them improved somewhere during the supply cycle.
Exactly. :)

My favourite examples are the door rollers and headlight resistors. The rollers changed from plastic to metal between model years. The headlights gained resistors in 2010. :)
 

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Well I've personally witnessed blower motor defects basically disappear after the 2010's. Somewhere down the line the manufacturer makes tweaks to lessen the percentages of failures. I believe there are far less defective blowers and the manufacturing of them improved somewhere during the supply cycle.

Some folks are going to have the blowers a little more prone to failure, some are going to have the slightly improved ones.

Had a blower motor, replace at 2010. 3 in now, replaced a couple weeks ago. Really doulbt MB, done nothing about the defect.

Head lamp resistor should be a recall too. Safety feature.
 

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Perhaps MB didn't change the blower motor, but something related (directly or indirectly) to it that's keeping it from dying in newer cars?
 

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Had a blower motor, replace at 2010. 3 in now, replaced a couple weeks ago. Really doulbt MB, done nothing about the defect.

Head lamp resistor should be a recall too. Safety feature.
I dunno. Maybe you got dusty old stock replacement blower? From the same production period?
 

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Lastly, you'll need to fill the gap between the new motor flange and the Behr motor flange to seal off the air flow. Weatherstripping works well. I also used a small piece of weatherstripping to plug the return air port that's located on the car.https://www.dropbox.com/s/5rnymlxq2tcapz4/Smart_blower_conversion.jpg
Do you have to plug the return air port? Does doing so eliminate the ability to turn on the recirculate switch? Sorry, not really sure what the function of the return air port is in the factory design.
 

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Do you have to plug the return air port? Does doing so eliminate the ability to turn on the recirculate switch? Sorry, not really sure what the function of the return air port is in the factory design.
All that port does is blow air over the armature of the motor to help keep it cool. That part of the design makes me think MB knew there was an issue with heat build up in the motor. First time I've ever seen a blower motor with forced air cooling... The new motor doesn't require that.

The recirc. door is on the opposite side of the HVAC unit, in the passenger footwell.
 
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