As noted earlier, the headlight switch plastic detented internals get brittle after 30 years, and begin to shatter and break apart. This necessitates replacement of the entire headlight switch unit.
My headlight switch noticeably started going bad in the 2021 time frame, and by 2023 it was in very bad shape, although it still worked. However, replacement was in order, and I had ordered a new MB replacement switch in January, 2022. I had it sitting on my garage work-bench for 3.5 years, but finally got around to replacing the switch tonight after dinner.
MB part number: 000 545 62 04. (current list $102; discounted ~$75-80)
DIfficulty of job: 3 out of 10
Time required for job: 30-60 minutes
Tools required:
- 1/4" ratchet
- 8mm socket (either deep socket, or with short extension)
- Phillips screwdriver
- Slip-joint pliers (or alternately, 24mm socket/ratchet combination)
Procedure:
Here is an overview of the headlight switch.
Note that my own car contains three extraneous switches - all relating to the BergWerks nitrous-oxide system installed some 20 years ago. The blue switch is the on/off for the bottle heater blanket in the trunk; the red and black momentary switches control the solenoid on the bottle that control the flow of gas to the engine.
For my own car, I removed the retaining ring and washer around the blue bottom on/off switch. This step should not be necessary for your car.
The first step is to remove the plastic headlight knob, by firmly pulling it straight off the central shaft of the headlight switch. Set the knob aside.
This exposes the large 24mm nut that secures the central switch shaft to the dashboard bezel. I used a large pair of slip-joint pliers to remove this nut by rotating it; others have reported success using a 24mm socket.
After removing the nut, pull the small central light bulb out of the center of the switch shaft.
After this, you should CAREFULLY prise up the bezel with your fingers. The bezel is in three parts - the headlight switch part; the curved part that goes over the top of the steering wheel under the instrument cluster; and the part that goes around the ignition key. All of these parts are connected by very brittle plastic hooks, so BE VERY CAREFUL not to break these hooks off.
After removing the bezel from the dash, you will see the brown wire with the black connector for the illumination behind the bezel. Carefully pull this black connector out and away from the back of the bezel, and set it aside.
Next, using your Phillips head screwdriver, remove the three screws that secure the parking brake handle bracket to the lower dash piece.
Next, prise off the steering wheel and ignition key surround bezel pieces, and carefully set them aside. BE CAREFUL NOT TO BREAK THE DELICATE PLASTIC HOOKS THAT CONNECT THEM.
Removing the bezel pieces exposes the five 8mm screws that hold the bottom part of the dashboard up. Using your 8mm socket, remove these screws, one by one. Note that the rightmost screw, above the ignition, is a slightly different size than the other four screws. This will be important for re-assembly.
After removing the screws, you can CAREFULLY and SLOWLY prise the lower part of the dashboard (knee bolster, under the steering wheel) downward with your hands. If you work it carefully, you should be able to create enough room to remove the headlight switch.
Remove the two long metal pins that hold the switch in its bracket by rotating the entire switch counter-clockwise. After doing this, force the dashboard panel downward enough to separate the switch from its plug on the back side, and carefully pull the switch assembly free of the dashboard through the opening.
After this, replace the switch by inserting it in between the lower dashboard and bracket, and plug the electrical connecter into the back of the new headlight switch. Then insert the switch into the bracket from behind, and rotate the long metal pins into their slots to position the switch correctly in the dashboard.
From here, re-assembly is the reverse of dis-assembly:
Insert and tighten the five screws to re-attach the lower dashboard to the dashboard panel.
Insert the lightbulb into the center shaft of the new switch.
Carefully re-attach the three bezel pieces above the steering wheel, ignition switch and around the headlight switch, ensuring their plastic hooks are inter-connected. Make sure you press the black connector for headlight bezel illumination, into the back side of the bezel.
Press the headlight switch bezel back into place, and re-instll the 24mm nut. Tighten it with the pliers. Then screw the three parking brake screws back in with the Phillips screwdriver.
At this point, you should be done. Enjoy your crisp and click-y headlight switch!
www.getmercedesparts.com
