Hi, heater box out of 82-85 euro delivery 240D. Defrost air outlet has a couple coils in it connected to a common ground, wires go to nowhere. I'll have 12V on them to see if the glow in a few minutes. Known or postulated function? Why disconnected (I'm thinking US import alterations)?

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CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

That is the speed control for the manually controlled blower. US 240Ds were the same.

The center knob goes from 6:00 to 12:00

At 6:00 the blower is off and an outside air flap is mechanically closed by a Bowden cable on the knob mechanism.

From 6:00 to 9:00 the outside air flap goes from closed to open as you twist the knob.

At 9:00 the first electrical contact is made, it applies 12 V to the entire resistance element and on to the blower. The blower runs at low speed.

At 10:30, the second electrical contact is made, this shorts out half the resistor element and now the blower runs at medium speed.

At 12:00 the third electrical contact is made, this shorts out all the resistor element so the blower gets full 12 V and runs at high speed.

__________________
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

Neat idea for a project in a 240D:

I wonder if a salvaged 124 blower regulator could be used to drive the blower motor in the 123 and eliminate the resistor pack. The motor in the 124 and 123 are electrically the same type motor (series motor) and I can't see any issues driving the 123 blower with a 124 (PWM) controller.

The regulator uses a variable reference voltage (0-6 V dc IIRC) to control the PWM regulator from zero to full speed. It would be a simple matter to fit a potentiometer on the back of the blower switch and use that to create a variable 0-6 V dc reference signal to the blower regulator.

Only other thing to watch out for, is that the regulator needs both sides of the motor connected to it and neither blower lead grounded. You would also have to find a place to mount the regulator so it is in the air stream so it can be cooled adequately.

Hmm if I still had a 123 I might be all over this...

__________________
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

Thanks. Have a pigtail crimped on to and into the compartment. Will make use of it or not as required.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?