I have a Ultraflex Caretaker 99 system problem. It is the 8 port system and was installed 10 years ago. The 8-Port Valve motor does not stop for any stations. It just spins constantly. On the control box the indicator light stays lit all the time. No mater what setting I put the controller on the motor does not stop, even in the pause position. I am thinking that it could be the photo cell sensor on the sensor plate, but am reluctant to order one without putting a meter on the system. Problem is I don't know what the readings should be. Any help would be appreciated.