anti-oxidation goop= vaseline,,,18 years on my other boat on all connections and not speck of green....one jar and a soft brush and your good to go....
i go through this twice a year , on my boat its the contact tabs that hold the bulbs . i just pull the bulb , sand the contacts ,make sure there is good contact and off i go. good luck
Had the same problem with mine. Then I tore everything out and replaced it all with nice clean connections and new wire. Work great now, took about an hour to do.