Question
I have changed the diophrams and celenoids on the two valves to my back yard now niether of them will work when I turn the stations on. The display will flash OFF. Im sure I re-wired them correctly?

Answer
RJ,
If the display is showing "OFF" then it isn't sending power to the solenoids. Either the controller is not working correctly or it may be sensing a short and shutting itself off.
I'd suggest disconnecting the wires to the valves in the controller. Then try to activate the zones. This will tell you if you have a controller problem or wiring/valve problem.

Matt