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

Fuse flashes when sprinklers goes on. Not all the time but approx. 50% of the time. Brand new pump start relay by Hunter products. Turned breaker off to pump. Still fuse on display. Disconnect common and zone wires from controller and ran a temporary wire to pump start relay. Still flashing fuse. Unplugged controller and unplugged everything that i could find on that circuit (including the freezer) and still same results. Also tried a new pro c controller and still had the same results. Only way I could get the controller to work is to take pump start wire off the controller(either clock).( A set up like a cty water system without a master valve). I checked wires for shorts and found none. I hooked up different solenoids and still same results. The submersible well is on a 20amp double pole . Line voltage at outlet was 119.4volts and zone voltage 26.2 volts The well is about 150 feet from start pump relay. What am I missing and what steps should I take? The only thing I think I can do is install a pump extrol tank with a pressure switch