Prius Rear Light Unit Condensation

[Chris Dance]

After washing my car I have just noticed the drivers side rear light unit is full of condensation and a few water droplets. ( Passenger side is OK,) Car is a Prius T Spirit; Aug 2014 model and as I am retired has only done about 1,400 miles. I had front headlight condensation on our Toyota Avensis years ago and had to have several headlight changes under warranty. I have never known a Prius to have a light condensation problem. I am contacting the dealer and hope he will change the rear light unit under warranty. Does any other member know of this problem on a Prius?

PS. The car was washed with buckets of water as my hose is frozen up.

[IanIanIanIan]

My nearside rear light had condensation in when delivered. I popped the lamp cluster and blew air from a hair-dryer (on cold) in one lamp hole for half an hour and the condensation went easily.

Never had any condensation again.

[Grumpy Cabbie]

In certain weather conditions both my rear clusters have a small (think inch square) of condensation in the top near the pointy bit. It soon dries out.

You could lose sleep over it or just ignore it. If it's significant condensation over a large area or large droplets (how big is a drop of water ;) ), then maybe get it looked at.

Doing such a low mileage I wonder if you have the climate system on recirc and the a/c switched off? Keep the a/c switched on in winter and if you use the Auto function the car will switch it on if the atmosphere in the car gets too damp whilst also keeping the car warm. That way it'll reduce any chance of damp in the rear which could cause excess condensation, some of which might find its way into your rear lamps.

I might be preaching to the converted but many people think a/c is only there to cool the car in summer. It actually does a damn good job of drying the air with heat in cold weather. It also barely registers in mpg's in a Toyota hybrid.

[Chris Dance]

Thanks for replies. I take your suggestion GC about keeping the a/c swithced on; thanks for that.

I garaged the car yesterday and I checked the rear light unit this morning and it was clear: no condensation. I did phone the dealer and they stated there has been no reports on rear light condensation on the prius. I have to take it in if it happens again. Will see what happens next time I wash the car.

[Grumpy Cabbie]

A cold and frosty morning up here and there was a small amount of condensation at the top of both my rear lights. I'm sure it'll clear away when the sun comes out.

I think a small amount will always occur. It's if it's really steamed up that it would be unacceptable.

[Chris Dance]

Hi GC,

The whole rear light cluster was "steamed up". If the unit is faulty it should show up again in the future, It only seeems to hapen after the car is washed.

[Grumpy Cabbie]

If the entire unit was steamed up then I'd tell your dealer and see what they'll do. It really shouldn't be steaming up to that extent.

[Chris Dance]

Washed the car again today. After washing there was condensation in both rear light units; drivers side was the most affected. I took the car to the dealer and they stated the rear light units are not sealed units so some condensation can be expected. The dealer rep stated that Toyota suggest driving with lights on for a while to clear any condensation. They can only change the light units if there is water in the base of the light unit. I said I never had any condensation in the rear lights of other Prius cars I had owned. The chap said the 2014 model had "face lift" rear lights and the new lights did get condensation. I have asked for my visit to be recorded. I would be interested to know if any PIP owners have condensation in the rear lights.

[Grumpy Cabbie]

lol driving with the lights on to clear the condensation? lol. That might work on old fashioned bulbs but with the LED's on the Prius? lol, that would be a no :)

(they run relatively cold)

[MEP's Yaris GS]

I would be interested to know if any PIP owners have condensation in the rear lights.

A small amount in certain conditions, never visible water droplets though.

[Carolynov]

I have condensation in the headlight of my 2009 Prius.

Can you tell me how to see the 9 replies to your post? I am new to the forum.

[FROSTYBALLS]

Hello Carolyn - welcome to Toyota Owners Club.

Your post is the first post on the second page of this topic. Scroll down towards the bottom of the page, where you will see 'Page 2 of 2 1 2' - click on the '1' and this will take you to Page 1 of 2.

[TheAdventureTravelers]

My 2012 Toyota Prius was filled with water from rains and carwashes.

Look at this video to see how I fixed it and how much water came out.