As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB-OUT, NR 3 ENG FIRE LIGHT AND FIRE WARNING BELL ACTIVATED INTERMITTENTLY THEN CAME ON STEADY. ENG FIRE CHECKLIST WAS ACCOMPLISHED. ENGINE FIRE LIGHT REMAINED ILLUMINATED. LOOP SWITCH WAS CHANGED. FOUND LOOP "B" ON NR 3 ENGINE TO BE FAULTY. DEFERRED LOOP "B" IAW MEL 26-2-3. DMI NR 23361. PLACCARD INSTALLED.