If the problem with the dryer is that the dryer works, but the timer dial won't move from the spot you set it on. You need to do the following to check it out. Disconnect the dryer from the wall outlet. Turn the dryer around or go behind and remove the controls back panel. This is how to check it with a multimeter:
Follow the wires from the timer motor to the timer. Disconnect the wires from the timer. Set your multimeter to read higher than 10,000 ohms. Take a reading between the two wires from the timer motor. The reading should be between 2,000 and 12,000 ohms. If the reading is infinity, the timer motor is bad and the complete timer assembly has to be replace. Checking it with a home made test cord:
Take an extension cord and attach 2 insulated alligator clips. Clamp the alligator clips to the two wires from the timer motor and use electrical tape to insulate the connections. Connect the test cord to the wall outlet and wait for 20 minutes. If the timer advance, then the timer motor is ok. If the timer motor doesn't advance, then the timer motor is bad, and the complete timer assembly has to be replace. Check my video below to learn how to check the timer motor properly. | 
