What was found
SENT TWO WINDOW AND COMBINED PITOT-STATIC HEAT MODULE ASSEMBLIES P5-9 TO BE MODIFIED AND TO BE REPAIRED FROM A PART NUMBER 69-37346-123 TO A PART NUMBER 69-37346-2123 FOR AD 2019-09-01 ICE AND RAIN PROTECTION. SENT IN THE FIRST MODIFIED UNIT THAT FAILED ON THE AIRCRAFT TO BAE THAT HAD THE LT ELEVATOR PITOT HEAT LIGHTS THAT WERE INOPERATIVE / STAYED ON. RECEIVED THE UNIT BACK AND IT IS DOING THE SAME EXACT THING. SENT A SECOND UNIT INTO BAE TO GET MODIFIED FROM THE -123 TO THE -2123 THAT WHEN INSTALLED ON THE MODIFIED AIRCRAFT PER THE AD HAD A FAILED FAULT WITH ALL THE PITOT HEAT LIGHTS FLICKERING ON AND OFF.