Hi All, I was working on my "New" ride and had to remove the panel under the driver's side dash.
While looking around I found a vacume line, red with a blue stripe, sitting there with a fuse inserted as a plug in the rubber connector.
The only possible mate I saw was an open black line coming through the firewall, which has a small fuel style filter installed in line with it in the engine compartment. When the engine is running there is vacume present at this line.

I put those two lines together, but now I am wondering it this is correct.

The climate control where I think the red/blue line comes from is type 3.
The black line tees off in the engine compartment with one side going to the EGR pressure converter. (CA Emissions?)
I am hoping someone out there is familiar with this and can shed some light on the orphan lines and where they need to connect.

I did check the online service manual and nothing seems clear relative to these lines.

Thanks a bunch in advance!

Happy New Year to all.
Ron Young

The black line should be a vent line, brought into the cabin to draw in fresh, clean air. No idea what the other line goes to.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Man, you must have the oldest 123 around.

Len

Need more specifics on were the Red/blue line was comming from and going to. One end destination or area would help. Ignition key area? Center console upper or lower? Etc. I have pictures of the dash out in stages and I can try to figure it out.
also make sure its is Red/blue not Blue/red. Small difference but a biggie.

The normal Red/blue goes from the defroster vacuum element to the side element. Attached is a picture of the connection down near the drivers area.

The other connection is up in the dash at the top. It controls the windshield element, or more accurately sections off from it. I'll post the pictures in a couple of reply's.

Dave

Attached Thumbnails

 

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

general location


If these do not help then we will need more specifics. A picture is worth a 1000 words.

Let your black line vent into the cabin and lets fix the problem you have.


You need to be looking in the AC section of the SM for info for this problem.

Dave

Attached Thumbnails

 

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

Hi Dave, That is it! No line to the side fitting of the vacuum element pictured. I hooked it up and freed the black vent line.
As an experiment I tried the various climate control settings both with and without the line connected and did not notice any significant difference.
I wonder why a PO plugged it????
Another MB mystery......

And yes, 1985 not 1895. But, just think what it would be worth.

Thank You again,
Ron

It was probably disconnected and plugged due to a leak in one of the elements. You need to get a Mityvac and test your elements. More than likely the unit that was disconnected, is the problem. Use the Mityvac to pull a vacuum on each side of the diaphram. Attach the Mityvac, pump it and you should, 1. be able to hold a vacuum, and 2. the lever coming out of the element should move. Vacuum to the other side of the diaphram and the opposite whould happen.
If one side will not hold a vacuum the element needs to be replaced. You cannot rebuild the unit, they are about $25.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

Dave:

Good idea on the Mighty Vac.
Just curious, where are you located?
I am in NJ USA.

FYI, My fleet

1931 Ford Model A Fordor (restored, sold)
1926 Ford Model T Open Touring (restored, sold)
1951 Bentley Mark VI (sold)
1976 Triumph TR6 (The wife laid claim to this one, or so she thinks)
1976 BMW 320I (My first new car! Sold)
1973 Jaguar Series 3 V12 (My Baby)
1985 MB 300 TD (new ride to save miles on my truck)
1999 GMC Yukon (sold)
2004 Dodge Ram 2500 4X4 (Work Truck)
2001 Volvo C70 (Wife's Daily Ride)
2003 Dodge Ram 2500 4X4 (Wife's horse trailer tower)


Now that I look at this I am worried!

Best Wishes for a great new year,
Ron