complete seat transplant 90' 420sel to my 83' 300sd

[thayer]

So. the 420 was blue with grey interior. Leather (so the heated seat elements are there)

First, removing the seats is very easy, 4 10mm bolts and unplug the 3 or 4 plugs.

Take your seats out the same way. there are many different variations (4 or 5) of w126 seats but here is the great news. THE COLOR OF THE WIRES IS ALWAYS THE SAME!!!!!!!! Which is such a relief.

Now, in my 83 the plug for the power seats is an 8 hole large gauge female plug. So what I did was I cut the sel plug with about 6 inches of wiring. I then added male ends to the spliced wires

Here are the different female plugs


Male connectors fit great


I had to bypass the main plug. when I got everything connected and tried to move the seat but all I heard was a click. there is a solid state "computer" that I believe handles the heated and memory seats.

Here are the plugs I had to use. there are all plugged into the computer



The Sex change so that the seat plugs would fit into the 83 plug


Match the colors(there are two per 90 plug and each 90 plug has three extra for memory so its going to be a nice jumble, zip ties are as high in my book as duct tape...actually I use a WHOLE lot more zip ties than duct tape).



Bolt the seats in, make sure your plug jumble has plenty of room to move as the seat moves.


I now need to go find the relays and switches with coin tray housing to get the heated seats warming.

Enjoy your leather seats....and keep your tex seats so that when your leather wears out you can put the tex back in. HA!