My center vents do not come on if at all until after I have been driving for over 1/2 an hour (by the time I sweat my way home). Everything else seems to work OK (fan speed, side vents, no air out of defrost vents). I am thinking that this may be a vacuum leak between the pod and the switch over valve.

Never worked on this before, any pictures/ advise on how to get to the switchover valve would be appreciated. Also, any other possible causes for this symptom??

__________________
1989 300E
103,500 miles

1982 300SD
Sold but not forgotten

It is likely the diaphrams in the pod. I had the same problem a few weeks back and fixed mine. You need to pull the glove box and what not to see the pods as they are behind the dash near the center console. If you search AC Vaccum issue you will find all sorts of threads on this.

__________________
86 300 SDL - Vesuvius

96 SL 500

Assumption is the mother of all screw ups.

Do not go gentle into that good night. Rage, rage against the dying of the light. - Dylan Thomas

All that is necessary for the triumph of evil is that good men do nothing - Edmund Burke

To replace the center vent diaphragm check post #9 here: http://www.peachparts.com/shopforum/showthread.php?t=12207&highlight=center+pod
The switchover valves are located behind the passengers kick panel of the console.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )

Sounds like a vac leak for sure. I would test all the pods with a mity vac before pulling them out. They should accuate AND hold vac, if they don't then they are bad. The one that controls the center vents is directly behind the two vents. Like state before you have to pull the glove box to see it. But you can test it without removing it.

__________________