As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE NR 1 GAUGE WENT TO ZERO WITH NO ASSOCIATED WARNING LIGHT WHILE IN CRUISE FLIGHT. THE PILOT IMMEDIATELY LANDED AT THE CLOSEST AIRPORT AND CALLED THE MECHANIC. THE MECHANIC INSPECTED THE ACFT AND FOUND SOME WATER IN THE 9 ALPHA CONNECTOR FOR THE INDICATOR. THE MECHANIC DRIED THE WATER FROM THE CONNECTOR AND CLEANED IT COMPLETELY. HE THEN HAD THE PILOT PERFORM A GROUND RUN WITH NO DEFECTS NOTED. THE ACFT WAS RETURNED TO SERVICE.