I picked up from a 230 (I think) W123 the heated seats' switches and just a few inches of the male - female wiring harness last summer. Pictured is the console but not the 6" to 8" length of wiring which went underneath the console. Started to rain like crazy and it was hot, so I picked up my tools and left. Came back a few days later, and the old girl was gone. Years ago I thought I found the heated seat swith and posted a thread with a similar looking switch only to be bashed by the MB crowed about how that was just a common RadioShack type of switch. Well, I found the real deal, althougth a few years later, and now missing the wiring.

Does anyone know about W123 heated seats ? I am thinking it will be way too challanging to actually find the correct W123 wiring harness which goes to the switches. But, who knows ? Maybe there's a part # and MB carries it. MB is supposed to always carry all parts for their cars, but more and more it's NLA ...

Would the wiring harness from a W124 or W126 be close enough to work ?

The replacement pads are old, if you could find them, but there are plenty of universal two-stage, high and low, pads out there which receive high praise on the net.

Not sure how the leather holds up over the years ?

I am thinking of installing these into China Blue because by the end of the summer she's getting new leather seat skins and new feintuft velour carpeting. This would be the time to install the heated seats.

I doubt I will ever use them, but with a new wooden console, what a cool option just to have without changing the character of the car or having a "mod" which sticks out like a sore thumb in a pristine survivor.

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I would not be surprised if they were offered in other markets. I have found some unusual featured on euro cars. One 300d i bought out of Dayton Oh had anti lock brakes.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I looked in the ETM for a 123 and it appears they were offered as an option.

Fuse 4 is the power source (live in I, II, or III)

The switches are arranged so that the seat pads (backrest pad and cushion pad) are connected in series for low heat and in parallel for high heat.

I found the wiring diagram online and it's pretty straightforward. No relays or control boxes like in the later models.

Later models may be harder to integrate with those switches, as the later models use a relay or controller to accept momentary switch inputs, whereas on the 123 the switches were maintained.

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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

A1078203017
Harness is listed for W107, but probably can be retrofit in a W123 as an option.
One listed on ebay dot de.

A1078203017 Auto Part Check - Look auto part number and get vehicle assignments | BenzCat.com

Edit: Looks like it would be pretty simple to build from used connectors, with the ETM diagrams as a guide for the pinout locations.

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

I cannot imagine any Radio Shack switch even coming close .

I hope you chase this down and do it .

Not what I'd ever need but it's a cool 'one more thing' to do.....

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

It does, or at least to me it did, and still does.

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A little late night investigation on the net and it looks like the heating elements are the following:

manufactured by: ZB Heizkissen, Part # 0008202198 ref# 30120418

A somewhat available, common part for the 124s, and other models. Not sure if it is really the same or not.

Looks like I could re-build the seats with the elements, and just have the wire runners hanging underneath the seats while I sort out the wiring. Now, looking for the correct wiring connectors for the elements.

Assuming the heating elements are available, which looks promising, the only missing piece is the end-plug (connector). Wonder how common this is ? See picture. I am pretty sure I have seen something like that on MBs over the years

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That plug looks like W123 era Mercedes. The one on the back of the console a few posts up does not.

Quite plausible that something like this was sold as a retrofit, regardless of if it was an OE option as well.its not hard to tap the fuse box, and add a few switches and heating pads into the seat pads.

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

These were a rarely-chosen factory option. I have them in my W116 300SD for the front and rear seats.


This is what the wire harness looks like.


You can use generic seat heater pads and then solder on the Mercedes pins and plastic, which are common two pin connectors.

The problem is going to be coming up with the connectors that fit onto the switches themselves, and then finding or properly making a wire harness.

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DON'T MESS WITH MY MERCEDES!


1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

I have the mail and female for the switches which go inside the console. I cut around 6 to 8 inches which I could 'pull' from under the console. It looks pretty straight foward. The pads themselves are still available, new. Just need to figure out the wiring.

PM Sent to you. Thanks for posting.

I have sourced the pads (new) which actually appear to fit inside the pleats. I have the correct switches. Need to figure out the wiring, which looks somewhat straightfoward.

On a W123 SA Code 872 was for rear heated seats. I found one example of this in Australia in a 280. It is somewhat rare. The pods are the same, however, from a W116 from what I could glean from the pictures.

Finding those pods is the needle in the haystack.

Have seen those plugs on the clearance lights of the w115's.

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Marc-André

W115 1975 300D "Geraldine"
W115 1976 300D parts/tutorial car

I just checked “Red” and they are on a bunch of items so planning a tour of southern junkyards and bringing my wire cutters

My late wife required heated seats in every car, so I put aftermarket kits on my W124 E420, and mounted kit switches on outside bottom seat trim. Looked good, worked fine, but dash mounted, Mercedes switches is a more elegant solution. The aftermarket kit took longer to produce desired heat through the padding, but wife said did the job and was satisfied. Don

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