ED...........these sealed headlamp's have a rubber vent tube on the backside for ventilation. It's possible that the one with moisture was mashed somehow when it was installed causing the vent tube not to breathe, JMHO. I would pull the lamp out and check it......happy trails and travel safe.
USAF 1959-1963/ JFK Innaguration parade 1961,
1997 Fleetwood Southwind 37Y, 460 ENGINE on FORD chassis, Power Platform with Tag Axle.