This is a basic question. Is it normal to have air flow from the center vents in all settings except off (O)? The diagram in the owners manual in the CD seems to indicate that in some settings there should be no or little air flow from the center vents. Is this correct?

TIA

Tinker

What year/model?

Sorry, 87 190e.

I don't know how the 190 works, but there is a description of when air is supposed to flow from which vents at the thread

http://www.peachparts.com/shopforum/tech-help/12508-blower-motor-replacement-procedure-300e.html

This implies that there should occasionally be times when there is reduced or no airflow from the center, at least on the 300Es. Good luck.

The european 190E has got a valve in the vent opening that can be (manually) closed and opened. If air is still floating through this vent when it is closed, the valve does not close entirely.
If you take a look through the vent grating, you can see an "imbus"bolt that is attached to the valve that can be closed. This bolt has to be tightened to let the valve close entirely; the valve can be "fine tuned" by this bolt...

greetingz,