Hey all, I have been un-glueing and re-gluing various interior wood and vinyl in my 300td and it is looking much better inside, the po used rubber cement and silicone caulk so lots of time spent scraping off old gummy glue today. I was scraping off the silicone around the climate control ( si was used to hold on the trim in lieu of screws) and and wondering why the climate control in the car was different than the one in 1979 FSM. I went over to the STAR sight and looked at the 85 model year FSM and there is my climate control



Was this climate control available in 79? or did this come with the om617.952 motor from an 84/5 model w123? , the befuddling hvac vacuum module of the 79's is present.

This climate control does operate in the defrost mode on high heat high fan speed, and the in ac mode the fan blows ambient air at high or medium speed through the dash vents. The wheel dashpot has no noticeable effect. Ac clutch does not engage but I have not checked the charge.

is that a picture of your car? that type of climate control was installed in w123 until 1980.

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1981 NA 300D 310k miles

Yes it is identical to the one in my car, I wish I had that radio but I have a "kenwood" installed by a trained monkey. I think I had my e-manuals mixed as I just looked at the 79 fsm and the above CC is there Well I got that figured out. There is a significant vacuum leak in the cc you can hear it under the hood when you shut off the engine, and it stops when the CC off button is depressed. The car will not shut off in bilevel. I'm guessing that may be part of the issue. Does anyone know about any AC compressor control modifications that need to be made in order to make this CC work with the .952's compressor.

When you are looking at the FSM online, you need to look at the start of each subsection to check what specific models/years it applies to. There isn't a specific FSM for each model year, within a model all the variations are generally included in the same general subject section, with subsections for variations (such as the two different automatic cc systems on a w123).

IIRC the later climate control is at the front of that section in the FSM and yours is about 8 pages behind it. I have it printed out, somewhere.

Someone explain that better if there is a better way to say it, I have only had one coffee.

By the way, your system is called ACC II aka the "evil servo" system. The later system with the horizontal pushbuttons is ACC III. I have no particular love for either (or for any ACC system), though the later one is infinitely easier to troubleshoot.

The index and overall functionality of the online FSM is directly from the CD-ROM version, which dates back to the early or even pre-Internet "multimedia" era and as such it isn't exactly state of the art. Mercedes didn't quite break the bank when they just slapped it up online as-is.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

Ya whoever scanned the photos should be flogged, they are about worthless. I am concerned about the evil servo system but what the heck I'll give it a whirl. If anyone has a link to a thread that details the evil servo

trouble shooting process please feel free to post it up. Also a readable vacuum and wiring diagram would be awesome.

Dang you beat me to it, I was going to post the same thing.

Here is a Google search of the Evil Servo. You can try other combinations of wording in the search.

https://www.google.com/search?q=mercedes+w123+evil+servo&source=lnms&sa=X&ei=0BndU9HRMIneoATD8oHoCg&ved=0CAcQ_AUoAA&biw=985&bih=657&dpr=1.3

This is the Images, click on a picture and that site will come up.

https://www.google.com/search?q=mercedes+w123+evil+servo&source=lnms&tbm=isch&sa=X&ei=EyPdU_yhOI6hogSizoGoBQ&ved=0CAgQ_AUoAQ&biw=985&bih=657

77 - 81 300D I believe used the verticle push buttons. Type two system, 82 - 85 300D used the horizontal buttons. type 3 system.

The servo was also used in the w116 and the w107.

The best system MB used was in the 240D`s with the manual type one system.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Thanks for those links I found a very nice link to a B and C manual section of the system I have. So I read it and headed out to the car to check out the individual parts and I found this,

the vac lines and wires are all there but the heater hoses are gone. The "Swapper" put manual inline valves in the heater hoses, they look like cable actuated valves? maybe from a 240, I will check when my wife gets home.


Sooo It will be much easier to remove the servo but I am scratching my head on where the heater hoses in the 79 used to run. anyone have photos? Diagrams? Thanks folks,
Michael

I just spent the morning reading a whole pile of print outs and many web posts regarding the evil servo, there was a mystical air to some of it. As I walked out to the driveway it was dead calm. smoke obscured the view, the pages were stacked neatly on the trunk of my 190D. A chill fell over me as I removed the vac-plug. The wind suddenly gusted and white paper flew up in the air and fluttered down all over the driveway....I quickly tightened the vacuum plug and the wind stopped... time to get a yellow binder. The Servo Gods Have Heard Your Prayers:

The smoke from canada is getting worse the sun is red and I am seeing more and more missing parts, all the heater hoses, aux coolant pump, vac modules etc...not to mention the horribly cracked ac lines and rusty looking compressor. There is coolant seeping around a frost plug behind the IP, and coolant leaking from the thermostat housing. I saw this album cover today at the thrift and it kind of sums up how I feel about this project right now.

There are threads out there describing various ways to bypass and modify the original system components and restore some functionality. High likelihood your servo is shot. Finding a working replacement servo for an economical price is gonna be tough. Not to mention the servo amp and other components that will probably need doing.

I say you'll most likely boil down your project decisions to wether or not the rest of your car is nice enough to put big money into the climate control restoration or go for some of the lower cost hack up limited functionality options.

Sweet album cover. This is the first time I've ever seen it.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

On my '80 model CD I swapped in a manual system from a 240d and also added Rollguy's Sanden compressor kit. The installation looks factory and works like a charm - no compromises. I'd bet, though, that a large part of the improvement came from cleaning out the evaporator coil (and the box it sits in). The easiest way to do the manual swap is you use the whole box and wiring harness from the donor 240d. The evaporators from both the donor and my original system were filthy and airflow significantly blocked - I guess that should be no surprise after 30+ years.

I've heard that you can still use the evil servo for a/c if you manualize the

Meant to add: I've heard you can still use the servo for a/c if you manualize the heat and that the problem with the servo comes from the coolant leaking. Another issue, though, is that (as I understand it) the compresor is always on with the servo - no "economy" setting.

Nah, you would have to buy a Coupe to appreciate that album cover. $500 door seals, unobtanium windshield, sagging door glass, even the doorjamb courtesy switches are different.

Your wagon is only in water up to its rockers, so far .

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22