If you are having troubles with your front door window regulators and they need to be replaced, this article will take you through the process step by step. To begin you will need to remove the door panel. Please see our article on removing your front door panel and complete the work there before starting this project. NOTE: make sure you lower the window until it is approximately 5 1/2 inches up from the lower molding.

If you have removed the door panel without lowering the window, now is the time to lower it so the top of the glass is approximately 5 1/2 inches up from the lower molding.

Unplug and remove the speaker from the door. It is held in place by three T20 Torx screws.

Next, you are going to be removing the airbag. If you have not already disconnected the battery and made sure the ground can not make accidental contact with the terminal you should do this before working on the air bag. Also make sure you wait half an hour between disconnecting the battery and working on any air bag system, this will give time for any residual energy in the system to discharge.

The air bag module is riveted to the door frame in three places. Use a drill bit slightly larger than the inside diameter of the rivet and drill them out. Make sure you use care as the window is directly behind the area you are working. Using too small of a bit and pushing too hard can lead to replacing the window along with the regulator. You are going to have to replace the rivets when you are reinstalling so you can either buy an inexpensive rivet gum or use small nuts and bolts. Just make sure you use some blue Loctite or Nylex bolts when reinstalling.

There is a small yellow electrical connector on the back of the air bag module that needs to be unplugged. Turn the air bag away from you and disconnect the plug. Always turn the airbag away from your body when disconnecting any air bag connections.

Drill out the four rivets for the door handle support and remove the support.

Carefully peel back the membrane from the door, leave the sticky stuff as you will need to reinstall this membrane later.

With the membrane removed you can see the six rivets holding the regulator to the door frame along with the two T20 Torxs holding the window to the regulator. Drill out the six rivets for the regulator. NOTE: on our project car someone had already drilled out two of the lower rivets and replaced them with bolts.

Carefully remove the two T20 Torx screws holding the glass to the regulator clips. Remove the screws which will allow you to remove the glass. No matter how carefully you remove the clips there is a good chance one of them will break so it is a good idea to order replacements before you start.

You can pull the glass up and tape it to the top of the door frame, but I find it easier to just remove it from the door and give it a good cleaning.

Remove the clip that holds the regulator cable.

The regulator sits in a slot. Lift it up and out to free it.

Turn the regulator sideways and lower it to the access hole in the door. Disconnect the wiring harness by squeezing the connection and pulling apart.

Carefully remove the regulator from the door through the lower cutout.

Installation is the reverse of removal. Don't forget to use some blue Loctite if you are reinstalling with nuts and bolts instead of rivets

Read the Full Article: https://www.pelicanparts.com/techarticles/Mercedes-W203/BODY-Replacing_Your_Front_Window_Regulator/BODY-Replacing_Your_Front_Window_Regulator.htm

Time: 2 hours
Tab: $0
Tools: T20 Torx driver, drill and bits, trim removal tool
Applicable Models: Mercedes-Benz W203 (2001-07)
Parts Required: New Regulator
Hot Tip: Get some spare window regulator clips
Performance Gain: Windows that work
Complementary Modification: Really clean the glass