As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT BROUGHT IN FOR VACUUM PUMP FAILURE. BEFORE REPLACEMENT OF PUMP DURING RUN-UP AND OPS CHECK, THE OIL AREA ANNUNCIATOR WAS INDICATING THE VACUUM SYSTEM AND THE VACUUM ANNUNCIATOR WERE INDICATING THE OIL SYSTEM. TROUBLESHOOTING DISCOVERED THE WIRES IN CONNECTOR J303 OF THE ANNUNCIATOR HAD BEEN SWAPPED. RESEARCH OF MAINTENANCE RECORDS REVEALED NO WORK EVEN DONE TO THIS CONNECTOR.