What was found
BOS - FLT 243 - ON TAXI OUT, ELEV POWER LIGHT CAME ON PRIOR TO TEST. DURING TEST, LIGHT ON, THEN OFF, NORMAL IND. WITHIN 30 SECONDS LIGHT REAPPEARED VERY DIM, BUT INCREASED IN INTENSITY TO FULL BRIGHT. SHUT DOWN LEFT ENGINE, NORMAL IND RESTARTED LEFT, NORMAL IND. RETURNED TO GATE. TRANSFER TO DMI NR 00568 IAW MEL 27-14. (M)