Outside air coming in thru dash

catonine · 10-27-2011, 08:32 AM

When driving there is a stream of cool outside air coming from under the dash. I have looked for areas of possible leaks but came up empty. All the potential air leak areas on the firewall appear to be properly sealed with spray foam. Anyone have any ideas or suggestion on where to look or what to do. This outside air leaking in is not so bad during warm weather but when it is cold outside, DW does tend to go on and on about it. Thanks John 2006 Monarch SE 30 PPD V10

Triker56 · 10-27-2011, 09:07 AM

During cold weather doesn't it change to warm air when the heater switch is turned to the Red area?

Diplomat Don · 10-27-2011, 09:33 AM

cantonine.......You need to stick some VERY bright lights under the dash when its dark. Go out to the firewall and see if there is any light. If so, use some spray foam and once its dry (next day), spray over it with rubberized undercoating available at your local auto parts store.

Also make sure that you're not getting any air leakage from around the doghouse cover. It could be blowing out the front of the cover and up under the dash. Generally this would be warm air, but in the winter, it could feel cold.

If all that doesn't work, buy her a blanket and a ski mask!

Rick Long · 10-27-2011, 11:00 AM

Push the recycle air button on the heater controls and it will more than likely stop the cold air. (only works while engine is running)

Batman_777 · 10-27-2011, 11:34 AM

I had cold January air coming in through the vents. I then set the air to re-circulate.. That fixed it.....

Update... I just looked above and noticed someone else had the same issue.

catonine · 10-27-2011, 11:42 AM

The air coming in has nothing to do with vents, it is finding its way in from the outside. Diplomat Don I have not tried what you suggest but will try and do that tonight. Oh, I tried to get her to use a blanket but she still grumbles about the air. Since nothing is on as far as the dash heater/ac is concerned I have not tried the recycle method but I will. This air leak does not bother me but since it does the DW, I really need to get it stopped if at all possible because while the air does not bother me, she does. Thanks, John 2006 MonarchSE 30 PPD

SKP Kirk · 10-29-2011, 03:59 PM

Could the leaks be into the heating/cooling system of the engine heater/air conditioner? Could air be bypassing the heater core and blowing directly inside from the vent or other openings?

catonine · 10-30-2011, 05:03 AM

SKP I dont think so. The air coming in is coming thru the firewall somewhere that a spot was missed when it was sealed up. I am going to take some expanding foam and apply it to all areas that I can get to that already have been sealed. I tried the sugggestion offered regarding a bright light but could not see any light coming thru anywhere. I have been trying to get this fixed from soon after I got the motorhome but nobody seems to be able to fix the problem. Thanks. John 2006 Monarch