Clearing up a foggy Nissan lens
This TSB applies to all 2001-2009 Nissan models. If a customer complains about water/moisture inside the exterior lamps, the issue may or may not be a problem.
All exterior lamp assemblies are vented to the atmosphere (not sealed). This is necessary to allow for expansion and contraction of air from temperature variations without damaging the lamp. Moisture in the atmosphere sometimes travels into and out of the assembly through these vents. The fogging/cloudiness should disappear over time when the assembly is in a dry environment.
Fog may temporarily form inside the lens (sudden temperature changes, car wash, etc.). This is normal. This condensation may appear anywhere on the outer lens, typically at its coldest location (lower corner).
If the moisture trickles, drips or pools, it may not be normal and the lamp assembly may have a water leak path. If large drops of water collect inside the lens, pull the vehicle into the service bay and turn on the low beam headlamps and hazard flashers. Monitor condensation in the lamps for 10 to 20 minutes.
If this condensation does not clear, replace the lamp assembly.