Part numbers for climate control 300sd

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

brujan@electrotex.com - 11 Feb 2006 22:12 GMT

Group,
Can any one tell me the correct part numbers for both the climate
control (in dash) and the temp control module (under RH dash) for 1981
300sd?
Thanks
Bruce Buchanan

Reply to this Message

Richard Sexton - 11 Feb 2006 23:30 GMT

>Group,
>Can any one tell me the correct part numbers for both the climate
>control (in dash) and the temp control module (under RH dash) for 1981

Manual or automatic climate control.

Signature

Need Mercedes parts ? - http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home page: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

Reply to this Message

brujan@electrotex.com - 12 Feb 2006 02:15 GMT

I did not know that there were two types. I guess automatic it's
suspose to be. These parts have been changed and I am having dificlty
with the temp control. It's all or nothing and now that I have the hot
water problem fixed I am looking into what I think will be a module
problem. Both the conrole center in the dash and the temperature
regulator (an electronic device under glove box) are both not origional
and could be non corect parts. My heat runs wild and will not shut off
the water untile I turn the wheel to MIN or the system to off so I am
guessing my temp regulator is kaput. Ido wan't to check that I have the
right parts in place first though before I go hunting another temp
regulator. My benz shop manule makes no distinktion as to any thing
else other than one type of system. I do not have a parts manule so am
not able to say for sure what the crect part numbers should be. Thanks
Bruce

Reply to this Message

Richard Sexton - 12 Feb 2006 04:17 GMT

>and could be non corect parts. My heat runs wild and will not shut off
>the water untile I turn the wheel to MIN or the system to off so I am
>guessing my temp regulator is kaput.

The automatic climate control is mosty for US cars, some Euro cars
had it but not many. In Europe the manual heat is prevalent; two
large dial on the console instead of pushbuttons.

The manual for the climate3 control system is LARGER than the body
and chasis manuals put together. The schematic for is is more complicated
that most earlier cars entire wiring harness. It's a right pig.

But, in realist only two things ever seem to fail: the monovalve
and the pushbutton assembly. The monovalve failure is way more
common.

This sounds like a monovalve failure to me. When they fail you get full
heat. When the pushbutton assembly fails you get nothing. There is one
rare mode of failure when no heat means monovalve, btw.

If youcan you can look at pulses to the monvalve. It's pulse width modulated;
if you can see the pule width change with no commensurate change in
temperature, it's absolutely the monovalve. Tha brain is sending tghe
right thing but that little bit of rubber in the monovalve, has, as they
all do, torn and is always passing full heat no matter what the setting.

http://articles.mbz.org/hvac/plumbing/monovalve/

I really would try this first.

The hot tip for a pushbutton asembly is to get opne off ebay for $40-$60. They
cost a fortune rebuilt and add a zero for new. Everybody buys used ones and they
work great. I doubt this is your problem though.

Signature

Reply to this Message

brujan@electrotex.com - 12 Feb 2006 14:21 GMT

I have checked the mono valve it is ok. I just got this car to heat by
replacing the mono valve. I have fought this car each winter for 3
years now. There was a home made heater control system in it when I
bought it. The controls have all been bought used to get it to start
working again. Till recently this car would onl;y heat if driven under
30 mph and freeze you over 30 that was fixed by putting on another mono
valve. Now I cook at all speeds. I guess that's better than
freezing but I am afraid that I am going to start going through window
motors now. When I hook a light to the valve I get heat with the light
off and no heat with light on. My problem is I cook as I drive because
the light never lights. If I turn off the heater the light is on. If
I click the wheel to MIN the light is on. The rest of the time the
light is on. The light will some times show some pulsing at first when
you first start driving but soon it is solid off. I have ohmed out the
sensors and they are in range of specs. I am just guessing but I think
it would be the fault of the temp regulator (a part I have put on used)
he is the guy that dose the pulsing I think. My regulator is 000 822
0903 and I have checked with one friend that has a 000 822 0303 this
may make no difference but I am about to buy another regulator and
would like to know if there is a difference between theses two parts.
Bruce

Reply to this Message

Karl - 12 Feb 2006 15:23 GMT

BTW, those 2 wires going to the mono valve:
One is hot all the time with the key on.
The other is ground and that is the one that is controlled.

When you loose the light and get heat, that is when it is getting ground.

> I have checked the mono valve it is ok. I just got this car to heat by
> replacing the mono valve. I have fought this car each winter for 3
[quoted text clipped - 17 lines]
> would like to know if there is a difference between theses two parts.
> Bruce

Reply to this Message

Richard Sexton - 12 Feb 2006 15:47 GMT

>I have checked the mono valve it is ok. I just got this car to heat by
>replacing the mono valve. I have fought this car each winter for 3
[quoted text clipped - 17 lines]
>would like to know if there is a difference between theses two parts.
>Bruce

Ah. This makes a diference.

The problem I had and fought two years was fixed when I replaced the
pushbutton assembly - everybody kept telling me to do this. I replaced
the monovalve (not broken) the aux heater pump, dicked arond for years.

Then I replaced the pushbutton assembly like everyone suggested and
goodlord the heat workls as advertised now.

Don't spend a lot of money one one. $50 max off ebay, but I would
strongly recommend you get one and put thesystem back tothe way
it was and start there; dollars to donuts it'll work just fine.

Signature

Reply to this Message

brujan@electrotex.com - 12 Feb 2006 16:53 GMT

I could not agree more. I started with Ebay. This car had a manual
hand valve for heat when I bought it and it had no AC at all. There was
no module, no monovalve, no pushbutton. I have replaced all of its
components with EBAY Great STUFF! Well I have had good AC for 3 years
now it will drive you out. First winter had heat with regulation but
it was a little squirrelly and some times would just suddenly run you
out fallowed by a cold spell and then return to heating. Last winter
that darn car would stop heating above 30MPH or over 2500RPM and
return to heating as soon as you lowered your speed, it liked to drove
me nuts but story turned short, a new mono valve kit fixed it. Now,
well, I got heat! It could be the push button but because some times
there is pulsing regulation for a few minutes (I drive this car with a
light bulb across the mono valve these days) I get the feeling that
what is supposed to be breaking the mono valve circuit in a rythematic
fashion has gone bizirkoid. All seems to be able to work but it is just
not willing to do it regularly. I am not positive but I believe the
amplifier is the brains behind this function. Do you know? I probably
plan to change the Module (amplifier) and push button both again. I
have to wonder though if I bought this problem on Ebay? The parts
worked at first but may have come with demons. I can buy a 000 822
0903 now for $40.00 I need to make sure this is a correct part first.
It is the same part number I have in place now, I would hate to
duplicate the problem over a part number being wrong.
Well thanks for lending an ear.
Bruce,

Reply to this Message