What was found
DURING A VISUAL APPROACH AT 1500 AGL, FLAPS 35, 3 GREEN & NO RED INDICATION ON GEAR AT THE TIME, RED UNLOCK LIGHT ILLUMINATED & GEAR WARNING HORN SOUNDED. DURING GO-AROUND, LEFT GEAR HANDLE IN DOWN POSITION & RED UNLOCK LIGHT WENT OUT WHILE 3 GREEN REMAINED ILLUMINATED. AFTER A SECOND ATTEMPT TO LAND WITH THE SAME RESULTS, BLEW GEAR DOWN IAW CHECKLIST. SUBSEQUENT LANDING ACCOMPLISHED WITHOUT INCIDENT. GEAR INDICATION THIS TIME REMAINED 3 GREEN & NO RED. FOUND FAULTY NLG DOWNLOCK SWITCH SG006. REMOVED NLG DOWNLOCK SWITCH IAW CHAO 32-30-03, REV 41. INSTALLED NEW SWITCH. RIGGED SWITCH. CYCLED GEAR SEVERAL TIMES. OPS CHECKED GOOD. WORK DONE IAW MM CHP 32-30-03, REV 41.