What was found
ON TOUCHDOWN, ENGINE FIRE AGENT LOW ALERT ILLUMINATED. TROUBLESHOT IAW FIM 26-21, SYSTEM CHECKED GOOD. NO HISTORY FOR 90 DAYS. ACFT OK FOR SERVICE. RAN TEST 4 TIMES NO FAULTS NOTED CHECKED BOTTLE, PRESSURE CHECKED GOOD, DID FIND ALOT OF DEICE FULID ACCUMLATED ON APU EXTERNAL EMEGENCY SHUTOFF SWITCH, CLEANED AREA. RAN TEST AGAIN NO PROBLEMS NOTED. IAW MM 26-21-04-5 CONTAINER, ENGINE AUXILIARY POWER UNIT FIRE EXTINGUISHER ADJUSTMENT AND TEST.