tion is not programmed into the controller. If simultaneous programming is not the issue, then the controller’s internal components have failed, and controller repair/replacement is most likely required. For locating field wiring shorts, the use of a ground fault locator and/ or wire tracker can be very helpful. Also, if you can’t locate the short, you may need to run a new wire path. If you’re lucky, the original installer may have left a spare wire in the multi-strand wire path. It is “nice” to leave a spare wire or two in the multi-strand cable for future repair or additions to the system. Thank you installers, for doing this! Locating short circuit and corrosion faults: Although the diagnostics for a short and corroded circuits is quite straight-forward, physically locating these ‘faults’ can be problematic. Overall, I would rather resolve a cut (open) wire issue than necessarily a short circuit issue. This is because determining the location of a cut wire circuit is generally both visually and “site digging activity history review” easier to find than are shorted wire circuits. Shorts can be very small or hidden Page 36
within a multi-strand wire bundle. Up to this time, all of your multimeter diagnostics have been at the controller. In order to locate the shorts, corroded wire, or wire connect faults in the field wiring, you will need isolate various aspects of the circuit. That is, you will disconnect the field wiring from the solenoid and measure their resistance individually. To do this, you will: (1) At the controller, connect that circuit’s terminal wire and the common wire together. (2) Go to the valve and isolate the field wiring from the valve’s solenoid by disconnecting the common and control wire. (3) Measure the resistance of the field wiring circuit back to the controller. If the field wire resistance measurement is higher than expected, the fault is somewhere in the field wiring and you will need to track that down. If the field wiring is healthy, you will measure a very low resistance of one or two ohms, indicating that the fault seems to be the valve’s solenoid. (4) Check the resistance of the