Rain Bird ESP-4TM with Hunter PSR-22: Pump Not Starting

ESP-4TM controller works (time, countdown) but pump doesn't start via Hunter PSR-22. All zones same issue.

Voltage Isolation Test

1. Zone active, measure 22-26VAC at controller: COM to Pump Start terminal
2. If NO voltage → controller failed
3. If YES voltage → measure at relay input (should be same)
4. If voltage at relay input → measure relay output to pump (110/220V)
5. If relay output good → pump issue
6. If relay output bad → relay failed
7. If controller-to-relay voltage lost → wire fault

Also Check

Pump supply voltage (110/220V at pump terminals).