PeachParts Mercedes-Benz Forum - View Single Post

Johnhef · #7 01-29-2008, 10:48 PM

Per the legality issue, I checked with some co workers and one guy said back in 96 when the 210's came out, they had a MB rep come down and show them the procedure to rewire the headlight switch to comply with the state's laws. This was in Virginia.

I however, did sucessfully rewire the fuse box in my 126 so my fog lights are unaffected by whether my brights are on or not. I followed the procedure provided in the link for the 123.

If that link ever goes dead, here's the description, with a few words changed to apply to a 126:

Fog light modification

A stock (Gen 1 US W126) is wired to supply power to the fog light switch only when the low beams are on. By changing the power supply for the fogs, you can run them anytime you like, even with the high beams. The power is fed by fuse number 6, which is a 16A (red) fuse. It also powers the right side low beam. By changing the power source to fuse 3 (left side parking lights), the fog lights have power with the parking light position on the switch.

Removing the fuse box to make this change can be a little intimidating. Be sure you DISCONNECT the battery first! There are two phillips screws holding the box in, and with a little work you can pull the panel out of it's housing. Be careful, damage to the wiring or fuse panel can be expensive to fix!

You'll notice that the connections to the back row of fuses is difficult to access, you may need to remove the connections to the opposite fuse in the front row. Make sure you remember where these wires belong and don't lose the screws! A magnetic tip screw driver is a must. The power for the fogs is gray with green and yellow marks (power for low beam is solid yellow). Clip the wire and use tape or some shrink wrap tubing to cover any of the wire that remains exposed. Carefully crimp/solder a new ring connector on the fog light wire and protect it with another piece of shrink warp. Then connect the wire to fuse number three, removing any wires you need to to gain access. The last step is to change the fuses. Swap the 16A from 6 with the 8A from 3. The fogs draw a lot of current, almost 8A by themselves. To help identify wires, you might want to get a copy of a Chiltons manual. They have a seperate schematic for the lighting system which is very useful.