I've learned a lot from this board and thought this would be my opportunity to pay it forward. One of the problems with dealing with 50 year old AC condenser blowers is brittle broken plastic and rusty housings because the interior of the blower is fully exposed to the elements.
Disassembling the sheet metal screws allows you to access the motor inside the plastic housing
The leads are soldered to the motor so they have to be clipped in order to free the plastic cover. Then the large clamp can be loosened and the 3 arm frame can be released.
Remove the jam nut on the motor shaft with an allen wrench and then support the back of the squirrel cage - I suspended it between two 1/4" pieces of plate steel. The motor shaft can then be driven out of the squirrel cage with a punch.
I cleaned the cage in an ultrasonic cleaner and then bead blasted it before having it plated in corrosion-resistant electroless nickel.
This was also an opportunity to powdercoat the housing in RAL Steel Gray, powdercoat the motor support, and clean the motor with CRC electrical contact cleaner. I then lubricated the motor bearings with krytox oil.
3D modeling of the motor housing and intake duct were done on Fusion 360 and the items were then 3d printed in PETG (temp resistant and somewhat flexible). The surface was treated with bead blasting to make it less shiny.
As printed:
After surface treatment with bead blasting:
Reassembly is the reverse process. After plating, the motor shaft will be tight going back into the squirrel cage - I used some nickel anti-seize on the shaft before pressing it back on and replacing the jam screw with blue loctite.
I tested the motor using leads clipped directly to the motor and touching them to a battery. I wouldn't use the connector on the black cable to test because the leads are very close together - which increases the risk of causing a short circuit is the leads should touch.
Then all that is left is to put a dab of silicone inside the motor cover hole where the cable enters and then reassemble with stainless screws.
The unit is now fully weatherproofed inside and ready to go back into the car.
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