What was found
NR 2 ENGINE SHORT CIRCUIT (FIRE LOOP "A") DETECTION CAME ON INTERMITTENTLY, ONCE SHORTLY AFTER TAKE-OFF, ONCE AT 3 HOURS. TRANSFERRED TO DMI LOG IAW MEL. PLACARD INSTALLED. NR 2 ENGINE SHORT CIRCUIT FIRE LOOP "A" DETECTION COME ON. INSPECTED NR 2 ENGINE FIRE LOOP AND PERFORMED ADJ./TEST OF NR 2 ENGINE FIRE LOOP PER MM. NO DEFECTS NOTED. DMI REMAINS OPEN FOR FURTHER TROUBLESHOOTING DUE TO HISTORY. TROUBLESHOT, FOUND FIREWALL FEED THRU CONNECTOR IN ENGINE SECTION DIRTY. CLEANED & TESTED SYSTEM PER MM. NO HELP. CONTINUED TROUBLESHOOTING, WITH LOOP "A" DISCONNECTED IN FAN COWL & CORE SECTION. FOUND SHORT BETWEEN PINS 1 & 3, AND 2 & 3 ON AIRCRAFT SIDE,