Tools Needed: Ohm Meter
Most potentiometers have three connectors. Two are the total and non varying resistance of the potentiometer, referred to as ends. The third is the variable resistance, referred to as the wiper.
If it is unknown which connections are which you can perform the following tests and determine their location.
Ensure that the meter being used for testing is equipped with a range capable of testing the potentiometer in question. Remember to always set your meter to one range higher than the component being tested. The potentiometer used in our video is rated at 1000 ohms or 1k Ohm, so we will be using the 2k setting on our meter.
If any of these tests results in an open or no reading the potentiometer is bad.
When taking a reading from either of the two ends and the wiper you should get a reading equal to the adjustment of the potentiometer. This can be verified by having someone adjust the potentiometer while taking a reading.
When taking a reading from the two end poles you should get a reading equal to the potentiometer’s rating, as is the case in our example, 1000 ohms or 1k ohm. This reading should only vary slightly if any when the potentiometer is adjusted.
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