Power SEAT Switch Mercedes 300sd SEAT Back Toggle – 1981-1982 Mercedes-Benz S-class W126

3D printable replacement power seat switch mercedes 300sd seat back toggle made for the 1981-1982 Mercedes-benz S-class W126: download the STL file and print a replacement for a cracked, lost or hard-to-find original part.

About this part

This is the replacement seat back toggle switch for the early W126 81-82 300SD. It fits inside the switch housing 1268202710. Both parts have become unobtainium. This little tang always breaks off on these early W126 cars. It is very delicate and was redesigned thicker on the 83 and up cars. After 40 years of use the toggle lever snapped off. I struggled for years epoxying on rods to the stub till there was no stub left. I had no choice but to design my own toggle.

There is another toggle elsewhere on Thingiverse but it only works on 83 and up cars. Mercedes went to a new design that easily plugs in and out of the car. On the 81-82 the switch is hardwired and soldered into the car. Thus it was important that I save the old switch and harness and simply replace only the toggle portion.

I reverse engineered the original toggle. To make the lever portion stronger I printed it hollow with the toggle pointing up on the bed. This would be the weakest way to do it but the hole is designed to take a piece of 1/16" welding rod. I had some stainless steel rod lying around and this acts as a reinforcement. It should be superglued in place. Do not insert it too far or you'll block the pivot hole. I used a drill bit in the pivot hole to space the welding rod back out of the bore.

When reassembling make sure to apply dielectric grease to lubricate and hold everything together during the assembly process. The assembly can be done while the switch is still in the door. This is critical because there are no plugs on the switch. It's hardwired in. I simply twisted the switch upright so I could work on it in the horizontal position while it was supported on it's wiring harness. Check the photos.

I realize most people with these old switches have already retrofitted to the newer style which is still available from Mercedes. The problem with doing this is you have to rewire the switch and buy plugs, cover plate, switch, switch caps and screws to assemble it as new. Another issue is you have to rewire and solder the harness consisting of many wires back together. It adds up to a lot of money so this toggle retrofit can save some $$$. It cost me $0.14 to print and prints in twenty minutes on my Prusa MK3. 100% infill of course.

I was inspired by this thing to fix my switch. Great job Hussein_I.
https://www.thingiverse.com/thing:5503779
The problem is the above is the new updated switch on the 83 and up cars. I only discovered mine was different after I took my switch apart.

Compatible vehicles

• 1981-1982 Mercedes-benz S-class W126

Always compare with your original part before printing. Fitment can vary by trim level and production date.

Specifications

Print settings

Standard FDM printing settings:
- Layer height: 0.2mm
- Infill: 70%
- Supports: As needed

What you get

A digital 3D model (STL file) of this part, ready to print on your own 3D printer or at any local print shop or online printing service. This is a digital download: no physical part is shipped. Not sure it fits your car? Contact us with your vehicle details before you buy.

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Design credit: original design on Thingiverse, licensed CC BY-SA-4.0.