Neighbor calls and says irrigation system worked fine last year, not working this season. So I run by for a look. He has replaced the timer(4 station), and replaced fence posts near where the control wiring goes around the foundation corner. There is an AVB near the foundation, but no pressure in the line there. Owner says he did not turn any valves off last year, and I was unable to locate a shutoff for the irrigation system out in the yard near the water meter, so if there is a valve box at the shutoff, it has not been opened for a long time. So, I break out the 521 locator, and trace/locate 2 valve boxes, neither with pressure at the valve(of course, because the AVB loop is dry, too). So now I'm thinking he's cut the control wiring with the fence post excavation and isolated a master zone valve and the other valves that I can't find. Next day, I run back with a shovel and gently dig up the wiring near the new fence post. Thank goodness, the owner did not encase them in concrete and there is a small nick or two, but the wires are continuous there. At that time, the owner tells me that he's not sure he wired the controller correctly when he installed it. Line wiring is correct, reading 29 VAC at the control terminals when a station is turned on. So I disconnect everything and ohm out the control wiring. Wire labeled #1 was on the common terminal, #2 on the the master(pump) terminal, and #3,4,5,6 were on zones 1 through 4. Here is my crude chart with the resistance readings:
Looks like he was correct about the wiring problem, #1 does not look like the common. What do you guys think is going on....shorted solenoid on #2 or #6 that might just happen to be the master valve solenoid? Looks to me like #2 or #6 should be the common, but both have low resistance across the page and the resistance across 2 and 6 is only 3 ohms.
Not sure what to do next, either break out the 521 again and hook up to #2 or #6 and try to locate the master again, or just start digging upstream from the AVB. Any ideas?
Skintdigit