As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FIRE WARNING DETECTOR INOP LIGHT ILLUMINATED IN CRUISE. FIRE LIGHT ILLUMINATED AND BELL SOUNDED. BLEW BOTTLE, LIGHT REMAINED ON. *S/D* FOUND WIRE IN APU FIRE WARNING HARNESS WITH TWO CUTS THAT WERE SHORTING. REPLACED WIRE CHECKS OK.