SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have an old (at least 20 yrs.) rainbird sprinkler system with three valves. After working flawlessly for many years, the system stopped working last year. I can turn on any valve by using the bleed screw. When I turn the controller on, though, I can hear the solenoid click and I can hear water running in the valve, but the sprinklers will not come on. I have taken the valves apart, cleaned them, and have taken the solenoids off and cleaned out the solenoid hole. I have bought a new solenoid and tried it, but no change. I have switched solenoids and still no change. Someone in one of these threads said to check the resistance in the wires. Does anyone know exactly how to do this and what the ohm readings should be? I believe I have a 24-volt system. I have stripped the wires and reconnected them, but nothing has helped. My backflow valve has a slight leak (drips) in it. Any ideas out there? I have a feeling it is something simple and I want to exhaust all ideas before I have to hire a professional. Thanks for any help!

The sprinklers work fine if turned on manually by using the bleed screw. I checked the electricity to the solenoids today and it is fine and the solenoids are working properly. Today I also went to the local pipe supply shop and they could not figure out the problem either. I think I will order new diaphragms for these old valves and give that a try. If that doesn't work I will dig out and replace the three valves. Does anyone know where to buy older model rainbird diaphragms? I couldn't find them at rainbird.com Thanks.....

Thank you. My rainbird is actually plastic, has a "horseshoe-shaped" solenoid, a bleed-screw in the center, and Glendora printed on the bonnet. From what I have read and from helpful advice like yours, I keep thinking there must be a clogged hole somewhere, but I have used a wire to poke in every possible hole and make sure they are clear. Thanks for the help.