What was found
DURING THE APPROACH INTO TEB ON ILS 6, WHEN IT CAME TIME TO SELECT GEAR DOWN AND DO THE BEFORE LANDING CHECKLIST, THE LANDING GEAR POSITION LIGHTS DID NOT ALL ILLUMINATE. AT THAT POINT, THE CREW EXECUTED A GO AROUND AND REQUESTED VECTORS TO TROUBLESHOOT THE PROBLEM WHICH WAS THE LANDING GEAR DID NOT INDICATE 3 GREEN, NO RED. THE LH MAIN LANDING GEAR POSITION LIGHT WAS NOT ILLUMINATED. AFTER FOLLOWING THE "LANDING GEAR WILL NOT EXTEND" CHECKLIST, THE CREW DECIDED TO DECLARE AN EMERGENCY AND PROCEED TO TEB AND LAND. ULTIMATELY, AIRCRAFT LANDED AND DIDN'T HAVE ANY ISSUE MAKING IT TO THE RAMP.