mariaml320

I Have A 2003 Ml320 ,the Front Defrost Has No Air Comin Out
I Have It Everywhere Else
Thanx Mike

lotmc

I had same issue with my 2004 ML270 CDI. Would only get air to the screen when the max defrost button was pressed on, but otherwise no air to the screen. Even with the max defrost button switched on, sometimes air would come out through the cabin dash vents and not the screen vents. I suspect the problem arose as the previous owner had the a/c on constantly, with the air set to come out through the cabin dash vents, and never selected defrost setting. A/C condensation inside the vents seems to have caused mould growth (I also had a bad smell), which over time seems to have seized the flap that should open to permit defrost setting. I may be wrong here, but the combination of mould smell from the vent, and the previous owner using a/c constantly with air set to come out the dash vents, had me convinced that the problems were related and caused by mould growth at the flap.
By pressing the max defrost button on and off regularly over a period of a week or so, I managed to fix the problem. Now I get air to the screen by selecting the screen vents, and without using the max defrost button. The smell that was annoying the hell out of me has also gone since the air flow to the screen has started - I guess that the mould has been dried and blown out by now.
Hope this makes sense - it was a really annoying problem for me, but is now gone!!