What was found
SEA FLIGHT: WHEN INITIALLY TURNING ON AIRFRAME DEICE BOOTS, THE OB TAIL LIGHT ON THE CAPTAINS SIDE DOES NOT ILLUMINATE CAUSING THE DEICE PRESSURE CAUTION LIGHT TO COME ON. AFTER PREFORMING THE EM CHECKLIST THE PRESSURES WERE 18 PSI. AFTER CYCLING THE SYSTEM A FEW TIMES, THE LIGHT COMES ON AND NO PROBLEMS THEREAFTER. MAINTENANCE PERFORMED OPERATIONAL TEST OF DEICE SYSTEM IN MANUAL MODE, TEST GOOD. ALLOWED DEICE SYSTEM TO CYCLE SEVERAL TIMES IN (SLOW). NO DEFECTS NOTED. NO DEICE PRESSURE CAUTION LIGHT ILLUMINATES. DEICE PRESSURE IS NORMAL THROUGH ALL CHECKS. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.