What was found
WHILE CLIMBING THROUGH 34,000 FEET, WITH THE APU SHUT OFF, THE APU FIRE LIGHT AND BELL ACTIVATED. THE APU FIRE BOTTLE WAS DISCHARGED AND THE LIGHT EXTINGUISHED WITHIN TWO MINUTES. THE AIRCRAFT WAS DIVERTED TO SDF WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND NO EVIDENCE OF FIRE. THE APU FIRE DETECTION MODULE WAS REMOVED AND REPLACED. AN APU FIRE LOOP WAS ALSO FOUND SHORTED. THE FIRE LOOP WAS REMOVED AND REPLACED, OPERATION OF APU FIRE DETECTION SYSTEM CHECKED GOOD.