i have a 2001 rogue trailer and i have replaced every light assembly on it at least once since i got it in august of 2000. im getting ready for a trip to shasta and after a quick light check i find both side marker lights are inoperative. i took off the lenses and found them to be corroded beyond repair and covered with this kind of turquoise colored crust. the bulbs for the tail lamps are incapsulated in a waterproof shell, they haven't got any water in them but the bulbs dont seem to last very long. for the last 6 months or so they have been in various stages of disrepair and i have just made due. thinking as long as i have brake lights and turn signals i'll be ok, but now that i have replaced them all, again (looks like disco trailer, i love it) i would like any tips on how to make them last a little longer. i will now start unplugging when launching....what about zincs on the trailer???