TXCLK

My 99 CLk has had this issue since I bought it. The air coming from the vents is hardly blowing out at the rate it should be, even on the max setting. The other issue is that no matter what setting you switch the vents to, there is constantly air coming up through the front window defrost vent. The two center vents also never have air flowing through them, the far side vents on driver and passenger side are the only two that have air flowing through them. Could this be a mechanical flap issue inside the dash or is it related to the control module? I live in south Texas lol and have black interior so I'd like to get this fixed before the weather warms up again.

MagmaRed55

Have you checked the blower motor and regulator?

aqeelr

have been having the same issue did a flap test a few times, seems a bit better, but no where as hard as its supposed to blow (from flap test)

TXCLK

How exactly do you perform the flap test?

aqeelr

I found instructions by googling it, but if i recall you need to be in position two, set both sides to room temperature (hit hot and cold button on at the same time) and then hit the rest and defog (i think, might need to double check this)

Serndipity

Mercedes w208 clk320 climate control vent flap test:


Also see:

aqeelr

so say i do all these tests and i find something isn't right, for example air coming on 0 regardless or hi/lo, what do i do?

MagmaRed55

I almost guarantee it's your blower motor regulator. Both my w210 and w208 had this exact problem and in both cases it was the regulator.

gregory13lil

You may even have a blockage at the blower with leaves amd junk....clean it out and see if it improves.

cindyclk

success!!! got a connector for reservoir and voila, center vent blowing AC!!! If you have a center vent AC problem, start at the vent distribution box under glove compartment...I tested it with my mouth to see if suction....if none...trace back to air reservoir hidden behind wheel well (https://mbworld.org/forums/newreply....=714194)...see pics..etc...back to vacuum connection at engine....if any leaks along the way, the vents will all open and middle one stays closed....as soon as vacuum attached to distribution box, they should all operate normally.