What was found
THE APU FIRE WARNING LIGHT AND BELL ACTIVATED ON SHORT FINAL INTO IND WITH APU START. THE APU SWITCH WAS MOVED TO OFF, BUT THE WARNING CONTINUED. THE APU FIRE BOTTLE WAS DISCHARGED, BUT THE FIRE LIGHT STAYED ON AND THE BELL WAS INTERMITTENT. THE AIRCRAFT LANDED AT IND WITHOUT INCIDENT. MAINTENANCE FOUND NO EVIDENCE OF FIRE. THE APU MUFFLER ELEMENT WAS FOUND SHORTED. THE APU MUFFLER FIRE DETECTION ELEMENT WAS REMOVED AND REPLACED, AN OPERATIONAL CHECK WAS GOOD. IN ADDITION, THE APU FIRE BOTTLE WAS REMOVED AND REPLACED.