As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GPS CIRCUIT BREAKER IS PROVIDING POWER TO MULTIPLE UNITS WHICH IS CONTRARY TO AC20-138A. AC20-138 STATES THAT GPS CIRCUIT BREAKER CAN ONLY POWER GPS. REFERENCE ATTACHED DRAWINGS FROM MFG WIRING DIAGRAM MANUAL. PAGES 34-20-00-01 AND 34-52-03-01.