Does The Cabin Air Intake Have A Water Drain?

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Recently while driving my 2005 Cabriolet at -10 C after a heavy snow, the windows became so fogged and iced up it became unsafe to drive.


Even the supplementary electric heat control didn't help, although the windshield did clear as the engine warmed up, but the side windows remained bad.


There was so much moisture in the car that it seemed that the cabin air intake had likely ingested snow which melted causing the high humidity.


I was wondering if any knew of there is a water drain for the cabin air intake and what are the chances of it being plugged?

Edited by smartdriver

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You can see the drain pipe if you look down cabin air intake.  

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To test, simply pour warm soapy water down air intake and see if it drains.

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Two typical water leak entry points on a Smart 450:


1) Rear quarter lights. Window seal can’t seal in way of a joint in chassis at top rear of window frame.  The joint forms a narrow shallow groove where water flows into cabin. 


2) In way of screw hole recesses for wing mirror interior trim. This is really bad design. Door seal goes over centre of screw recesses. Water runs down outside of door seal, then flows into screw recess and drains inside cabin onto forward end of door sill and under carpet. 


Fix for 1) above is to remove window, clean and refit having applied a small amount of sealant to joint area in chassis. 


Fix for 2) above. I cut a foam ear plug to size and push into recess hole then seal hole with about 2” of good electro tape. 


Run hose test before and after preferably with Smart car owner present. 



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