No, the fuse doesn't blow the instant it is replaced. This problem has been going on for several weeks now. Initially, a fuse would blow after the system had gone through several zones. My landscape guy replaced two solenoids after testing all 6 and made sure all the wiring was tight. We assumed that would correct the problem.
Unfortunately, after running through a complete, I returned to the unit later and found the PR OFF message again. He came back and ran it through each zone with no problem. He then suggested that we turn the dial to OFF and leave it there. I left it alone for several hours without a problem and then ran through another cycle without incident.
Turned the dial to OFF again, came back the next day and the PR OFF message was back again. So, the question remains, why would it blow a fuse when it is in the OFF position?