I’ve noticed slight condensation inside my rear tail lights on my 21’ P4x and on my 23’ Rock Creek Pathfinder after I run through a car wash or after a ton of rain. No issues with the lighting or anything. Brought to attention of Nissan Dealer. It was early one morning and almost every car on their lot had some minute amount of condensation buildup inside the lights. Perhaps they are not sealed 100% airtight for an engineering standpoint (pressure, heat, etc). 🤷🏼‍♂️ When I do see it, it’s gone extremely quick so hopefully nothing bad will come of it.

 

Roger that. Thanks. I can see the logic of a "flex fit" for lack of a better term, but moisture and electrical connections have always been at odds in my experience. If that is part of the design, it leaves me wondering how the bulb seat stays free of corrosion. 🤷‍♂️

 

As long as it's just fog and not water droplets running down the inside of the lens then it's normal. Just to be safe you can remove the tail light and inspect for any cracks or damage on the back of the housing. Post a pic here of the condensation if you can, that will help.

 

10-4. Thanks. I'll keep an eye out for it and see when it next shows ... what happened just before etc and take pictures.

 

Photos.

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That’s way more than I ever see…

 

thats alot

 

Roger that. Thanks. I'll look into pulling the assembly and tracking down the opening that's letting in moisture.

The right side is dry - no problem.

 

Had that happen once on my other truck, it was a lose bulb letting the moisture in.

 

The condensation issue resurfaced, so I removed the lens again today and filled it completely with water to look for leaks.

No leaks, but I did notice a blue patch over a hole that, on examination appears to be a weep hole for evaporating moisture. (Photos below).

After dumping the water I left the lens assembly open in the sun for several hours to dry out.

The gasket on the lower bulb is “hard” so I used a bit of painters tape to improvise another layer of gasket material.

It’s all back together. I’ll see what happens the next time it rains. Tap-a-talk does not sort photos in order, so these are random.

Homegrown gasket layer

Different angle on the painter's tape application.

In this photo the lens assemble is literally full of tap water (took about 1.75 quarts, for those with inquiring minds). Notice the round, aqua blue patch over the hole that is seeping moisture. There is one for each of the three sections, and they appear to allow moisture to escape.

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Yep definitely more moisture than a normal. There is a crack somewhere. There seems to be a visible crack in that first photo you posted.

 

Hmm. I think I see that now that you have mentioned it. I’ll look closely today.

I’m curious about how and when it would have gotten cracked as I had not previously observed water. [emoji2373]


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Well, the line that appears in the photo is not a crack, but an internal part of the housing and lens unit. It is present in both sides, and the right side is moisture free.

I’m thinking that I’ll have to remove the L unit and then look at the backside for a place where moisture can gain entry.

In the meanwhile it is a warm sunny day so I’ve parked the truck with the left rear corner to the sun. I’ll look later today and see if it cooked out any of the humidity.


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Check if the seals/gaskets on the bulb connectors are damaged. I never saw any visible moisture in my 18 P4X that I recently turned in.

 

Roger that. I’ll be browsing YouTube later this evening to alleviate surprises on the chore.

Then we are expecting sunshine and pleasant temps most of next week so I’ll carve out a midday session to get’r done.


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And one more question - finding and sealing the entry point is one angle, but before that, what are the suggestions for evaporating out the moisture that is already there?


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Remove the tail light assembly. If you have a air compressor, you can blow air into for a few mins to dry it up fairly quick.

 

You don't want to seal it up with any moisture left in that light. You could put it in the oven on a cookie sheet at a very low temp, if the wife would let you to remove all the moisture. Or wait for summer and set it out in full sun for a while.

 

or a hair dryer

 

Isn't there a vent of some sort? Sometimes those plastic plugs you see are actually vents. Vents plugged?
Temps go up and down wildly. I'd imagine some sort of condensation is normal.
I've gotten some condensation in my P4x tails since day 1. It comes and goes. No major droplets.

 

Isn't there a vent of some sort? Sometimes those plastic plugs you see are actually vents. Vents plugged?
Temps go up and down wildly. I'd imagine some sort of condensation is normal.
I've gotten some condensation in my P4x tails since day 1. It comes and goes. No major droplets.

I thought about the vent angle and looked closely and couldn’t spot one. But that might be my Covid-stroke affected eyesight. I see fine 10 feet and 10 yards and 100 yards out, but have difficulty with small spots up close.

I took it apart this morning and let the lens cook a while in the sun, blew it out as best I could with the compressor and then reassembled. All the big droplets and most of the condensation is gone. Photos appear below in random order.
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Edits for explanation

The lens once removed. Very simple - held in by two screws. Remove the screws and then gently pry the lens to remove. The pins fit into grommets in the body.

Note the grommets for receiving the pins on the backside of the lens assembly.

I used a pair of cheap jeweler's glasses to look for cracks in the assembly, and twisted a blue shop towel into a wick to soak up water.

The two holes to the right are part of one "compartment" within the lens assembly. After wicking the standing water out, I was able to insert an air-blower attachment into this section and flow air for drying.

Note the water puddled in the lower corner. Tap-a-talk uploads photos randomly so this one should actually be up top someplace in the sequence.

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Interesting. I'd check the seals on the bulb sockets. Maybe they are dried out.

 

Yes. I thought of that as I was removing the bulbs.

Years ago I watched as a Louisiana friend filled his john-boat with water to spot the leaks. After he marked them he drained the boat and let it dry, and then broke out the silicone.

I only had an hour or so to give to the task, but I plan later on to take it apart and fill the lens assembly with water to see if I can spot an entry point. If I can rustle up the part numbers I'll replace those seals at the same time.

Note the edits in the photos post.

 

my passenger rear lens has a split so we will see if i start having issues. who knows when it got there, or how, but so far no watter has gotten in while going through the car wash or when it rained so much of hte drive to virginia and around that area a few months back.

and i know the split is through completely because i pushed it and you could see it flex all the way away from the other side of the crack.