TC reported Rear M2 car DMI indicator was not lighted up. ~~~~~ To further rectify.     1534 & 2534 Semi-permanent coupler electrical head contact pins cleaned. Function test - OK. #2534 DMI able to illuminate. Fault cleared.  Alan/Lee PT/Shafie 44322 2534 TC reported DMI indicator was not lighted up. CE: DMI indicator not lit. Suspect Blown. TIMS show all DIR OK.  533/534 measured the following : #2534 junction box #1E line 5601 - 108 vdc #1534 junction box #2E           - 23 vdc #1534 junction box #1E           - 18 vdc #3534 junction box #2E           - 22 vdc Suspect #2534 & #1534 semi-permenant coupler line 5601 having high resistance. OPS 20 raised to follow-up.  Au TK 44322