There are little Hygroscopic Discs under the rain sensor cap that expand when they absorb water which in turn caused the spindle they are on to press against a switch that bypasses the sprinkler system. These discs eventually get thicker and do not return to their smaller shape. You can get a replacement for $10 which includes a new spindle, cap and discs that should fix the issue. You might be able to get them to work by removing a disc or two, but I think it is better just to replace them. My unit is about 15 years old and I thought it that issue, but it turned out a wire spice went bad and the rain sensor started working as soon as I re-spliced it.

Although it has not raided, my unit still show off when I switch the unit to Active. What could it be that;s causing this unit to do that

my last name is dowd hmm so i wonder ? :thinking emoji: