As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AIRCRAFT TOOK OFF AND 10 MINUTES INTO FLIGHT THE LT RPM WAS VERY ERRATIC AND THEN STOPPED INDICATING. AIRCRAFT RETURNED TO BASE AND MAINTENANCE FOUND A BROKEN WIRE ON THE BACK OF THE INSTRUMENT CONNECTOR. WIRE REPAIRED - GROUND CHECKED SERVICEABLE AND AIRCRAFT RELEASED TO SERVICE.