What was found
CLIMBING THROUGH FL370 - FL390, POWER SWITCHED FROM CLB TO MCT ON ITS OWN. SHORTLY AFTER RECEIVED A LT ENG CAUTION & LT N2 WENT TO 0. ALL OTHER ENG PARAMETERS NORMAL. AFTER A COUPLE OF SECS, CAUTION DISAPPEAR & N2 WOULD RETURN TO NORMAL. IT DID THIS REPETEDLY & WOULDN`T STOP. FOLLOWED QRH & DID AN INFLIGHT SHUTDOWN IAW QRH. COMPLIED WITH SM 72-00-00, FAULT ISOLATION 46. CLEANED ELECT CONNECTIONS & SECURED ALL RELATED ELECT CONNECTIONS IAW FAULT ISOLATION 46. PERFORMED OPS CHKS. OPS CHKD GOOD. WORKED IAW AMM PART II, 71-00-00 & SM 72-00-00 FAULT ISOLATION 46 PROCEDURES,