How does my heating/cooling system work?

[Mistel]

I have an 85 Euro 300TDT with AC. I think the only difference with a North American car is I have dual controls for driver and nagging wife. The wife is complaining that there is dust coming out of the vents, most noticeably through the defrost vent, and the black dust accumulates on the dashboard. So what I want to do is try to clean the vents somehow to lessen the dust coming out of them. What I was thinking is blow some compressed air through the system and try to blow it clean. I tried dropping the blower motor and blowing some air in but it didn't seem to be coming out anywhere?

Short of taking the whole dash apart, is there an easy way to clean the system? Are there parts in there with foam on them that are disintegrating? Where is the fresh air brought into the system?

Thanks

Peter

[nscarr]

peter--did you blow the compressed air while the vents were open? my understanding is that the vacuum system will close the vents when the car is off--i could be wrong there, tho... -noah

[dmorrison]

The system has a black foam on the panels. It is disintegrating. A bit of a pain but not a problem. Try blowing the system out with a compressor. It might help.

Dava

[Mistel]

Thanks for the replies

Dava, I saw your pictures of when you took your dash apart, so I guess you are the guy to ask. This foam you mention, where is it and can I get at it without taking the dash apart?

Thanks

Peter