As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLT AT FL330 WHEN POWER WAS REDUCED TO DESCEND, LOWER AFT BODY OVERHEAT LIGHT FLICKERED THEN CAME ON STEADY. COMPLIED WITH RED TAB PROCEDURES, LIGHT WENT OUT. SYSTEM TEST SATISFACTORY. MONITORED FOR REMAINDER OF FLIGHT. REMOVED AND REPLACED FIRE DETECTION UNIT PER M/M 26-14-00-5, OPS CHECK NORMAL. A/C OK TO CONTINUE SERVICE.