Toro Vision II: One Zone Shows 24V Constantly But Won't Water

Toro Vision II controller: one zone reads 24V constantly (on or off), suggesting valve always open, but that zone doesn't water. System holds air pressure (winterizing), confirming valve is stuck CLOSED.

Voltage at Controller ≠ Voltage at Valve

The controller terminal shows 24V, but that doesn't guarantee the solenoid receives it. Wire damage, corrosion, or a bad splice can allow voltage reading at the controller (open-circuit measurement) while preventing actual current flow to the solenoid.

Diagnostic Steps

1. Locate the physical valve for this zone
2. Measure voltage AT the solenoid wires (disconnected from solenoid) while controller activates zone
3. If 22-26 VAC at solenoid → Solenoid or diaphragm issue
4. If low/no voltage at solenoid → Wiring problem between controller and valve

Why Valve Is Stuck Closed Despite Constant Controller Voltage

The controller output driver for this station is likely failed in the ON state (leaking voltage). But if the wire is broken, the solenoid never actuates. The constant 24V reading is the controller's failed output transistor leaking, not a true signal.

Fix Both Issues

• Repair/replace wiring to the valve
• Have controller checked/repaired for the stuck-on output
• Replace solenoid if it's also faulty