Touch the red (positive) lead of the multimeter to the positive end of the wire windings around the motor. Touch the black (negative) lead of the multimeter to the negative end of the wire windings around the motor. The reading that appears on the multimeter screen is the resistance in ohms.
How do you test a motor with a multimeter?
To test your motor for short to ground, you’ll need to set the multimeter to ohms and disconnect the motor from its power source. Then inspect each wire and look for infinite readings. Alternatively, if you get a reading of 0, you might have a cable issue.
How do you test a 12v motor with a multimeter?
Touch the red, negative (-) wire of the voltmeter to the red, negative terminal of the battery. At the same time, touch the black, positive (+) wire of the voltmeter to the black, positive terminal of the battery. Read the voltmeter’s display. A fully-charged car battery should read 12.6 volts at room temperature.
What is the most common cause of motor failure?
Low Resistance. The most common cause of motor failure, and arguably the most difficult to overcome, is low resistance. Low resistance is caused by the degradation of the insulation of the windings due to conditions such as overheating, corrosion, or physical damage.
How can you tell if a 12v motor is bad?
If the meter still reads as an open circuit after the shaft has been rotated, the conducting brushes may be bad.
- Touch the leads of the meter to the two motor leads.
- This type of ohm reading will indicate that the motor is good and the problem resides with the electrical circuit itself and not the DC motor.