I started my sprinkler system for the summer. I turned the main valve on. All four zones came on at once but with very low water flow in most all heads. The fuse looks good. I shunted the fuse but the system still had all 4 zones going. I turned the main valve off and disconnected the transformer AC adapter, plugged the transformer back in and turned the main valve on again. All 4 zones still came on. What is wrong?
