Would you please clarify whether the RCM repair or replacement works if there is no battery activity?

Here's my situation. Have had my '08 roadster for one year. No problems until a hellacious rain storm a month ago. Dropped over an inch of water in less than an hour. Lillian was in the parking lot and got drenched. Went to start her up, no lights on dash. Got a jump; she starts right up and I had no problems until this weekend. No less than three times after being parked that when I returned no power. Crazy thing is when I lift hood or release hood latch, power back on.

Mechanic has no idea what to do. Previous post mentioned cars where dash lights are on. Could this also apply to me?!