As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TROUBLESHOOTING FAULTY FIRE WARNING LIGHT, FOUND 3 DETECTORS INSTALLED WITH BUTT SPLICES, CONTRARY TO KA200 MAINTENANCE MANUAL, CAUTION NOT TO SPLICE SOME WIRES AND USE ONLY SEALED CONNECTORS ON OTHERS. REPLACED DETECTORS AND REMOVED SPLICES AND PINNED TO FORWARD PLUG. WORK DONE AT APPROVED FACILITY, YET, ACCEPTABLE DATA WAS NOT FOLLOWED.