What cause the light to go out
Answer Felicia, We presume you mean the drum light WE4M305. The circuit to the light bulb and socket is controlled through the door switch
WE4M415. When the door is closed, power is routed down to the motor, so the dryer runs. When the door id open, the power is routed to the light bulb and the light illumintes.
We keep cracking the plastic control knob because the timer shaft is too difficult to turn.
Do we need to replace the timer unit?
Answer Hello Paul. Yes, if the timer is hard to turn, and keeps breaking the knob, you will need to replace the timer WE4M377. Hope this helps.