Troubleshooting Vacuum Cleaner Motor Failures

　　Whether it's the exhaust blower motor or the brush roller drive motor that's failing, there are steps you can take to troubleshoot the cause of your vacuum cleaner motor failure. Here are three reasons why you should consider this:

　　1) Defective switch - The vacuum cleaner may have a defective switch that is not allowing voltage to reach the suction fan motor or brush roll drive motor. You can use a multimeter to test the switch for electrical continuity - there is a continuous electrical path through the switch. Make sure the multimeter is properly calibrated, then set the multimeter's selection dial to the lowest setting in ohms of resistance. Connect the one-meter probe to the switch terminal and the second probe to the other terminal. Now turn the switch on and off. If the meter display indicates zero ohms resistance when the switch is in the "on" position, the switch has continuity and should be functioning properly. However, if the switch tests "negative" for continuity in the "on" position, you'll know the part is defective and should be replaced with a new one.

　　2) Burnt motor - If the on-off switch test is energized normally, the next step is to determine whether the motor itself is burned. For suction fan motors, try turning the fan blades or blower wheel by hand. If the blades or wheels are not turning freely, the bearings in the suction fan motor may be stuck. If you suspect a brush roll motor failure, loosen the brush roll drive belt from the motor shaft and try turning the brush roll by hand. Does the brush roll rotate freely? Then, the bearings in the brush roll motor may have seized again. Since the motor bearings cannot be repaired or replaced, you will need to install a new motor to service the vacuum.

　　3) Broken motor brushes - but what if the shaft of the fan blades, blower wheel, or brush drive motor turns freely? Then there is one more thing you can check. Some electric vacuum cleaner motors will have two motor brushes that conduct current between the motor's stator and rotor. One or both of these brushes may be damaged, preventing the motor from running. Depending on the model, you may be able to fix the problem by replacing the brushes rather than the entire motor. We recommend replacing both brushes at the same time so they wear evenly.