Advance motor - This motor only received voltage and operates when the controller is changing stations and when returning the station dial to the rest position. When checking to determine if the motor is receiving the proper voltage, be sure that the motor is supposed to be engaged at that time. It may be necessary to apply the correct voltage directly to the motor from another source to verify operation. Before doing this, be sure to disconnect the motor from its existing power source! If the motor does not turn it will need to be replaced. If it does turn, then it is not receiving its proper voltage. Check the primary power and transformer.
Micro switches - A micro switch is a small switch that when activated, instructs the controller to perform a certain function. When there switches fail or are out of adjustment the controller will not perform as programmed. To determine if the switch has failed, turn off the primary power to the controller and conduct the following resistance test. Using your volt ohm-meter, check the switches, the resistance should be below 2 ohms when closed and infinite open. When micro switches fail they tend to not make contact when they should be closed. The resistance test will read several hundred ohms or higher when closed. The switch must be replaced and readjusted.
The button of the micro switch should not be depressed until a program pin is locked into position to activate the switch.
Wafer switches - The wafer switch is the distribution point for the valve voltage. As the center hub turns with the station dial, the valves receive their voltage one at a time. normal wafer problems occur when dirt accumulates on the tab or the contacts. This prevents the voltage being sent to the valves, or the valves turning on and off sporadically during their operating cycle. The wafer switches may be cleaned using the eraser end of a pencil, being careful not to bend any of the contacts. Be sure to check and clean the back side of the wafer switch. To do this it will be necessary to remove the two mounting screws and lift the wafer switch off of its shaft. When excessive wear occurs on a wafer switch, it is possible for the tab to break off. When this occurs, the switch will need to be replaced.