The dryer "flags" are in the thrust pro follower that contours the vehicle. These flags must turn on and off with each dry cycle. They monitor the air flow to make sure both motors are working. The flag is mounted to a limit switch and these need to be lubricated to keep them from sticking. After spraying lubricant on the pivot shaft, work the switch back and forth to make sure it will move freely. If you are unable to free up the switch you may need to replace the head.