If you handle some of the basic appliance repairs around your house, you may very well be able to figure out what is causing your dryer to not tumble. There are three main issues that could be causing this problem – a bad pulley idler, a bad motor, or a bad or off-track drum belt.
Inspect the Drum Belt
Since this is the easiest fix, start by checking the drum belt. After unplugging and removing the back panel of the dryer, look inside for the belt connecting two pulleys. This is the drum belt. Run your hand around the belt to feel for breaks or chunks of missing rubber, and to find out if it is on the pulleys properly.
If the belt was not positioned properly and you didn't feel any damage, reposition the belt on the pulleys and test the dryer. Just be sure to keep your hands clear of the working parts of the dryer during the test.
If this fixed your problems, there is no need to continue. If the belt is in good condition and was not off track, continue on to check the idler pulley after unplugging the dryer again.
Check the Idler Pulley
Between the drum and motor, you will see a small pulley. Gently lift the pulley toward the drum. This will release the tension on the belt and allow you to remove the belt from the idler pulley. Manually turn the pulley to get a feel for how it moves. Does it turn smoothly and easily? Does it appear to have any damage?
If the idler pulley appears to be in good working order, your problem most likely lies somewhere in the motor. Reposition the belt on the idler pulley and unplug the dryer once more before moving on to testing the motor.
Test the Motor
On the motor you will see two wires. Disconnect those two wires and get your multimeter out. Touch each lead with a probe to get a reading. The reading should be zero or close to zero.
Now, use the multimeter to test the ground. Touch one probe to the metal motor housing and the other on one of the two terminals. You should not be seeing any readings. Remove the probe on the terminal and touch the opposite terminal. Again, you shouldn't get any reading.
If the motor failed these tests, the motor needs to be replaced.
Talk with a local appliance repair professional like A OK Appliance Service if you need further assistance getting your dryer tumbling.