1990 Mercedes-Benz 420SEL Q&A
1990 Mercedes-Benz 420SEL Question: How do I attach the power window regulator to the window?
I would let a professional do it. It can be tricky taking the door panel off. I had mine replaced by MAACO. - Visitor
1. If you have the door panel removed. Cut the power wires to the power window motor. 2. Adhere clear 2" tape to the window and the door to keep it from failing down, have it in the up position. Make sure the window is clean so the tape will stay on it. 3. Remove the power window motor via the two 10mm bolts and one 10mm nut. 4. Remove the two 10mm nuts for the window track guide. 5. Pull out the motor and armature. Becareful not to break the window. You will have to move the guide out of the way. 6. With the motor and armature out of the car, grind off the old regulator off of the arm from the power window mechanism, making sure that you do not grind off more than what is necessary. 7. The new regulator can be removed into two pieces, the white pieces. Remember how they go together. 8. Find a level and sturdy area. We use our saw table. You will need additional hands, one person to hold the motor and the other to strike the pin on the regulator. 9. You will need a hard round metal brace for the inner/under side of the regulator after it has been removed. Place the regulator on top of the this round metal (it has to be smaller than the regulator, so it doesn't break it. It has to be just the same size as the larger side of the pin. 10. Place the pin side of the regulator in the armature, making sure it is in the right side up. 11. Now you have the round metal brace underneath the regulator for bracing it. Now take a punch and hammer. Hit the pin until it has flatten down onto the armature. Becareful not to damage the regulator. 12. Assembly the two pieces of the regulator together, make sure that you have the two black rubber pieces go in there as well. 13. Now go in the reverse order to put the motor back into the door and connect the wires. 14. Test your work. - Visitor
You should never ever have to cut anything on these cars! Don't cut wires! Ever! If you're talking about the plastic slider that runs back and forth in the metal channel at the bottom of the window, I have done this repair a number of times. I posted a short article, with pictures, on a Benz forum: http://www.benzworld.org/forums/w126-s-se-sec-sel-sd/1464233-replacing-broken-plastic-guide-window-2.html Essentially, you have to drill or grind out the stud that held in the plastic and replace the slider. You can buy one from Mercedes or an aftermarket dealer, or you can make your own from simple parts you can find at Home Depot. - Wayne_M