Abstract: A method and apparatus for trouble-shooting an irrigation system having a plurality of independently operable irrigation branches and an automatic controller for control of water flow in the branches is disclosed. A radio transmitter and a radio receiver are tuned for the transmission and receipt of two differing signals. The receiver is electrically connected to the controller at a position between the timing apparatus and the rapid station advance motor and at a position enabling direct actuation of water flow. The radio receiver produces output signals actuating the controller in response to the received radio signals. Thus, one radio signal is used to select the branch of the irrigation system through which water is to flow, and the other radio signal is used to trigger flow of water in the selected branch.