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Looking for a smaller 12v DC motor (convertible top drive)

Looking for a smaller 12v DC motor (convertible top drive)

I've looked through DigiKey and Mouser and can't find this. I just picked up a BMW 135i with a rusted out convertible drive motor. It's 2" in diameter x 3.3" long with a .246" shaft with a single "D" for the connection to the pump. It has tapped holes in the face for the adapter that bolts it to the pump. Any suggestions where to get this? There are no markings on the motor.

RE: Looking for a smaller 12v DC motor (convertible top drive)

That looks pretty common to me.. I suggest you look to ebay for that. "DC motor 12V" and see where that leads.

There are dozens of Beemer convertible drive mechanisms, including their motors, being hawked on ebay.

Keith Cress
kcress -

RE: Looking for a smaller 12v DC motor (convertible top drive)

That rusting may be cosmetic. I would disassemble the motor and clean and lubricate it. Make sure the brushes are free to move easily. Lightly clean any rust off of the rotor and magnets, being careful to avoid removing any of the parent metal.
If the motor is not burned out it may be salvageable.
I have seen motors in much worse shape than that that ran fine.

"Why not the best?"
Jimmy Carter

RE: Looking for a smaller 12v DC motor (convertible top drive)

The back cap is crimped into the housing so I'm not sure if it can be disassembled without tearing it up too bad. I will try, though. When I turned it by hand it was pretty crusty but smoothed out after a couple turns. The resistance reading was still open, though.

RE: Looking for a smaller 12v DC motor (convertible top drive)

Thanks for your suggestion because I got the old motor running today. I got the back cap off but couldn't get the crimped/rusted plastic terminal cover out even after soaking with penetrant. So I decided to try putting power to it again and it worked! There must have been some crud built up on the commutator and banging around on it broke it loose.

RE: Looking for a smaller 12v DC motor (convertible top drive)

Thanks for the feedback.

"Why not the best?"
Jimmy Carter

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