One Zone working one zone isn’t

I’m hoping someone here can save me some money from calling out a technician. One of my zones is working and the other isn’t. I went into the wiring and all connections on the controller side appear to be solid. I took the wire from the non working zone and swapped with the working zone and that eliminated a controller issue. For the sake of this post the yellow wire is the non working wire. Going to the box outside I checked all of my wire nuts and the connection appeared to be good but I went ahead and put a new solenoid on the valve that is assigned for zone 1. The new solenoid has allowed a very small amount of water to make it to the first sprinkler head but not even enough to pop it all the way up. Any ideas??

@Frlancdu - if you have access to a multi-meter (AKA volt/ohm meter) test the resistance down the yellow wire when disconnected from the Rachio and back through the Common wire. Resistance should be around 35 ohms. If it is more then there may be corrosion or something else interfering with the amount of current.

Also, were waterproof wire nuts used on the wires when replacing the solenoid? Waterproof wire nuts have a gel in them to prevent water intrusion. If not, I might undo the wiring connections, clean them and then remake the connections using waterproof wire nuts.

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The waterproof wire nuts used to come in smaller packs not the 20 pack as shown above.

I would still double check the things @DLane suggested. If everything seems to be fine . . . with the solenoid appearing to work, but no pressure . . . the possibilities that come to mind are:

  1. a broken pipe
  2. if the valve has an adjustment on it, maybe it is almost closed
  3. if the valve has a filter on it, maybe it is clogged