This may sound like a really silly question but i have noticed that on my car (82' 240d) i have the passenger and driver climate control knobs. They each have temperature and then one knob in the middle for power (and then vent slider nobs too).

I noticed though above that DIN there is another knob that is a scroll wheel that is blue and white. Blue says max and white says 0. What does this scroll wheel control(close to the antenna up/down button)?


Thanks.

The scroll wheel is to turn on the AC.

Charlie

__________________
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

so what is the nob on the nobs on the bottom for (that go from red to blue)?

Bottom two knobs are for heat control, the upper temp wheel is for the air conditioning I believe.

__________________
2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

I used to have an 83 240d and the manual is not very clear as to how to work the levers for directing air flow and the graphics aren't very helpful on the panel.
Here's how they work:
Upper left lever, above driver temp knob, lever to left = defrost fully open, to right = minimum defrost
Upper right lever, above passenger temp knob, fully to right = floor vents fully open, to left = floor vents shut.
Lever on dashboard below center vents, to left = outside air intake open, to right = outside air off.

Left and right blue/red knobs control the water valves to the heat core. In the blue position the valves are totally shut and in the red position the valves are totally open. The heat core is split and the car actually has dual zone temperature control.

The center knob is the outside air flap and fan speed control. At the 0 position the outside air flap is shut and the fan is off.
Between 0 and 1 the outside air flap opens and the fan is not operating. This allows ram air to flow through the vents.
From 1 to 2 to 3 the fan is operating with increased speed.

So in a nutshell here is where to put the levers:
Defrost: both panel levers to left, dash lever to right
Heat, no defrost, both panel levers to right, dash lever to right unless you like a little fresh air then push towards the left
If you need half and half heat and defrost then push both panel levers to the outside
In summer both panel levers to center for a/c operation and dash lever to left (pushing this to right cuts off conditioned air flow).

Max position on ac thermostat dial engages electrical contact that trips vacuum solenoid to operate recirc flap in air box behind center vents.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Sounds like an Owner's Manual would be of value here.

Ebay? Some salvage yards resell them. You may even find one left in a car!

Another very helpful book is the parts book for your car, which has exploded diagrams of all the parts (but no part numbers, those are found in the online EPC - Electronic Parts Catalogue).

Lastly, the April 1985 edition of the Technical Data Book is an absolute treasure trove of data on 123 cars, including torque values and test values and data about nearly every aspect of your car including fluid capacities, performance data, towing capacity. There is enough data in that little book so that a well-trained mechanic can repair virtually anything on the car without referring to the service manual. You'll probably need to call the Classic Center in CA to order it.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

jay bob is this the setup you are talking about?

Attached Thumbnails

 

also jay_bob if i find my temperature creeping up towards 100c, if there a certain position to maximize the cooling effect for the engine? (sometimes this happens on really hot days in stop and go).

Thanks!

Thank You this is indispensable information !

Here is an old thread for back in oh one...(2001) they had problems back then too
trying to figure out how the 240 system works.

240D climate control operation?


Charlie

sent from my pos computer

__________________
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

Yes, turn the heat on, this will send what coolant you have to the heater, which is just a heat exchanger, or radiator, inside. Thereby allowing more cooling to the engine.

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83 SD

84 CD