Because they refused to give away such frivolous extras to American drivers. I;'m happy to just have single-speed intermittent wipers on my diesels. I had to add right-hand mirrors to both of my 240Ds because those didn't come with them!

Happy Motoring, Mark

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DrDKW

Yes, power seats and vacuum adjustable head lights are much less frivolous.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I suspect it's the same reason the steering column isn't height adjustable... Mercedes figured out the perfect wipe interval for all people in all road conditions

Personally, I prefer my old cars to be as gadget-free as possible. My '60 Fintail's only 'option' was a power-brake servo. It didn't evan have a radio when I got it.
None of my diesels has power seats, though one of the 240Ds does have power windows.

Speaking of which - Supposedly, back in the late '50s, a Mercedes spokesman was asked why Mercedes didn't offer power windows and other options that were becoming common on American luxury cars.
His response "If you can't roll down the windows, you shouldn't be driving!"

Happy Motoring, Mark

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DrDKW

Lance,
Thanks for the info...

__________________
"I have no convictions ... I blow with the wind, and the prevailing wind happens to be from Vichy"

Current
Monika '74 450 SL
BrownHilda '79 280SL
FoxyCleopatra '99 Chevy Suburban
Scarlett 2014 Jeep Cherokee
Krystal 2004 Volvo S60
Gone
'74 Jeep CJ5
'97 Jeep ZJ Laredo
Rudolf ‘86 300SDL
Bruno '81 300SD
Fritzi '84 BMW
'92 Subaru
'96 Impala SS
'71 Buick GS conv
'67 GTO conv
'63 Corvair conv
'57 Nomad

Me too, which is why I have a 240D with manual everything, transmission, windows, sunroof, no AC, etc. I think that one more, slower, intermittent wiper setting would not have made the car that much more complex though.

They must not get light rain in Germany.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

From reading the third page of the guide that Forced Induction posted it looks like every time you use any speed other than intermittent the intermittent wiper speed will be reset, likely to the maximum 30 second delay. Is this true?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I don't think I've ever seen any W123 sold in the US that didn't come with factory airconditioning. My second 240D, 'Beirut Taxi' has manual tranny, manual windows and no sunroof. It does have manual heat & AC though. Was your AC removed?
(I noticed in you signsture that your 240D now has some non-original equipment)

Happy Motoring, Mark

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DrDKW

Well, whenever if you set the switch to position or II or III it is the same as selecting position O. To change this would require making changes to the car's wiring harness. Not good.

So, if you have a delay set and move the switch to II or III for X seconds and move it back, you'll wind up with a delay of about X seconds. If you keep it there for 45 seconds or more, it will revert to the "default" delay, which I have set to about 7 seconds.

I chose not to violate the prime directive - "thou shall not mess with the wiring".

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Bob
'82 300D Petrol B-G Metallic

Ahh, excellent. I knew someone had to be annoyed as much as I am.

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85' 300D

It had an aftermarket unit fitted that I removed when I added the non-original equipment. It was a Euro Delivery program car, so the original owner must have not ordered factory air.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

You are right, it's not very hard to reset. Do you offer a package deal with this unit and the tach amp?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Guys, I just want to clarify some things here. Mercedes made some considerable modifications to the pulse wiper systems since they were first introduced in the mid 1970s. There has been a "progression" of different pulse wiper control relays during the history of the system, and this little upgrade module I've made has been tested to work with SOME of them.

The first incarnation of the relay is part number 123 821 00 63. It is shown in the first photo labeled "Old Style" below. The only manufacturer I've found is Bosch, and my module works with it. It was used in the older W123, newer W114, W115, and W116, and W107s between about 1975 and 1980. It's housed in a metal can and it's a ***** to work with, but it does work.

In about 1981 there was a simplification done to the relay, resulting in part number 000 821 08 63 (you can sometimes find parts labeled 000 821 07 63). This is shown in the second picture and is a plastic housed part. There are multiple manufacturers like Bosch, Siemens, LK and others. It was used in later W123s, later W107s and W126 through 1985.

Big changes happened in 1986, when the relay changed to a "multifunction" relay similar to that used in the W201. Based on my reading of the limited documentation I have, this new multifunction relay controls not only the interval wipers, but the rear defroster as well as some level of emergency flasher function. The control is to some extent digital, in that the relays I have taken apart use a single IC to control all of the function.

I had intended to do the work necessary to integrate my upgrade module into the multifunction relay, but in order to do this I need some documentation above and beyond that which I already have, such as car wiring diagrams, etc. Early last summer I had enlisted the help of this forum's (and likely the world's) foremost expert on the SDL, but I DROPPED THE BALL and failed to follow up. In order to make this a reality for the multifuction relay, I need to trace wiring diagrams to decode functions, reverse engineer circuit board layouts to figure out how to integrate my circuit into the existing frameworks, and build test fixtures to ensure my upgrade hasn't degraded any of the non-related function. The amount of work needed is substantial.

Anyway, at this moment if your car uses a relay with a part number of xxx 821 yy 63, where xxx is either 000 or 123 and yy is 00, 07, or 08 then this work is already done. This should cover almost every car made by Mercedes between 1976 and 1985 - with the glaring exception of the W201.

Attached Thumbnails

   

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Bob
'82 300D Petrol B-G Metallic

Dumb question: where under the kick panel is the relay? I was trying to pull one from a junkyard 450SE for a core but could not find it.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

In the W123 the relay is behind the dash located approximately halfway between the fuel gauge and the firewall. Take the kick panel off and reach up and feel around.

The W126 has it under the hood, drivers side, in a box with a bunch of other relays.

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Bob
'82 300D Petrol B-G Metallic