W124 300D vacuum hoses going into/out of cabin??
 

The W124 car had all the vacuum hoses messed up going into/out of the passenger cabin.

I can only think of 4 hoses going into/out of the cabin.

1) Vacuum shut off TO ignition switch ( brown )
2) Vacuum shut off FROM ignition switch to IP ( brown )
3) Vent into cabin ( black )
4) Climate control into cabin ( green )

There seem to be an extra one ( white ) laying around. Any idea what could it? Or it is just the mess up left over from PO.

There's a vacuum line to the rear headrests. I forget if it splits ahead or aft of the bulkhead. Doesn't the black VCV vent line go into the cabin separately from the shared EGR and ARV vent line?

Is the white line attached to anything on the engine? It might be left over from a boost gauge.

Sixto
87 300D

I do not want to mess with the dash or the under dash panel to see where the white line goes. It seems to go near the hood release handle somewhere. It is too much work to find out.

Anyway, I connect a mityvac to the white line and it holds vacuum, so it is connected to something inside the cabin. Same for the green line. All the climate control pods seems to be working OK. So I decide to join the white and green hose together. There does not seem to be any side effects.

Test the rear headrest release with the white line connected and disconnected.

Sixto
87 300D

Sixto - you are spot on. The white line is for the rear headrest. The green line is for the climate control. I tied them together and now everything works.

Thanks

If you're lucky, you'll also have purple. That's for the adjustable Euro headlights.
Blue is for coupe seat release.