Troubleshooting a Vacuum Motor

Test and Troubleshoot the Vacuum Motor:

You need to troubleshoot your vacuum motor if it gives you problems before splitting it open trying to fix it. You should handle your cleaning system carefully to avoid messing it up. Opening up Your Vacuum Motor

  • If all you hear from the vacuum unit is a click at the when you try to start the vacuum motor from inside the house, then the motor in the unit is dead and has to be replaced.
  • A strong odor from the shellac, which coats the copper coil windings, is an indicator that the motor is about to or has burnt out.
    • If the motor is still running, even if it turns on and off by itself as it is cooling and heating, you can still run the motor until it gives up for good. Note: This may make the thermal mini breaker burn out, and then you'd need to replace it or the entire circuit board.
  • If there is no odor, you will need to turn the vacuum on and observe the motor. If you see lots of blue sparks, read about the motor brushes below.
  • If the motor is out of the vacuum unit, delicately hot-wire it with direct 110 volt leads.
    • Two leads are going to the motor - one black and one white or two black. Use these wires and disregard the green one if there.
    • Hotwire with a patch cord (an AC cord with a regular electrical plug on one end and two alligator clips on the other end) and hook one lead to each of the motor wires (motor wires are not polarity sensitive). Note: Be sure the motor is raised so the air can enter the motor's bottom.
    • If the motor still has some life in it, it will start, but if it is going bad, it will only work for 10-15 minutes or less. If it doesn't start at all, it is obviously bad. Sometimes slapping the motor or vacuum unit will jar the motor and get it to work again for a few minutes. Intermittent motors should be replaced.
    • From experience relays and transformers rarely go out. It is usually the motor that burns out, often does so quickly when at life's end.
  • Take the time to check all of your wire connections - hours can be spent diagnosing a vacuum only to find out it was a bad connection.

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