W124 300TD Help needed finding where vacuum pipe go´s !

[mutley666]

I noticed when poking around near the fusebox that a vacuum pipe was not connected.
I traced the other end to the small rectangular box on the side of the diesal pump, photo shows this.
The other end looks like it goes into a large rubber bung with 4 other vacuum pipes on the bulkhead behind the instument cluster.
I removed the ins´cluster and could not find anything where this plastic vac pipe connects to? It only pokes through 4 to 5 inches behind the instrument cluster so maybe it connects somewhere else in the engine bay near the fusebox?
My car has the climate control with AC.
but everything seems to work ok?
Any ideas?
Thanks.

 

[jonnyboy]

photo to big to see on my netbook but could it be the one to the light levelling switch? that always used to be vacuum controlled

 

[Mercedes cozy]

the one on the side your pointing i believe only collects clean air and its not connected.