W126 ('88): Blower Fan vent options: problem
 

Recent problem on blower fan for a/c:

My center dash vents do not blow any air. In all settings, air flows through top defroster vents and side vents. Nothing can change this, no matter what setting.

Fan speed buttons oeprate fine.
Can switch from a/c to just economy without any problem.
Is this a vacuumm hose thing or a fuse?
But man, with summer coming, would love to have air flow back through the center vents.

any ideas?

Thanks!!

This is a vacuum thing. The system defaults to your condition when there is no vacuum. You probably have a vacuum element leaking. The A/C position requires the defrost doors to be held closed, the center vent held open, and at least one stage of the recirc door pulled. Any leak from these posible elements causes all of them to relax to the default position. This position is defrost for safety reasons; thats the best thing to be stuck on.

Thanks, Steve.

any ideas based on experience as to which line I should check, and where it is lcoated?

I thank you - and value your experience greatly.

Remove passenger upper kick panel , look along the side of the center console , you will see there is one screw in the rear . remove that screw , now the panel clips into the center console, gently tug it toward the front of the car. After removal you will see a block that has vacuum lines on it . You will need a hand held vacuum pump. Go to each of the lines and see if they hold. Note which ones dont . You will need a vacuum diagram after this. Just let us know and we can get you one.:D