TLC #116 B – Did you Know? … WIRE INSULATION … CAN also LEAK!
Be aware that instantaneous differential pressures caused by sudden 100°F+ Temperature changes can actually force air as well as water through the inside voids of any Trailer Wire Insulation.
When a “Truly Hermetically Sealed Chamber” is absolutely required, the “Wire Strands” entering the Sealed Chamber, must not have any insulation gaps in order to guarantee an airtight (hermetic) seal … meaning that each “Whisker” of any typically used Stranded Wire must be reliably “Potted” to guarantee an always working Hermetic Seal.
If only the outside surface of the Insulation Jacket is Potted, sufficient paths will still exist for water and air to be transported back and forth inside the Insulation Jacket because of extreme thermal/pressure variables, which are commonly present in any “LED” or Incandescent “hermetically sealed” outdoor application.