Mercedes-Benz Forum banner

foglight trouble shooting

2041 Views 12 Replies 3 Participants Last post by  siguy2k
Ive been searching quite a bit and havent been able to locate any info on the testing procedure for the fogs. Ive looked thru the online manual links i have as well. Both bulbs good. All other lights work. Fogs will not. I was going to check for voltage at bulb but didnt get to it today but if there isnt any, which im sure theres not, then i couldnt follow the wiring far enough. Help is appreciated. Also im confused on euro and us headlights. I thought the euro were h4 bulbs. Ive got clear corners and 9004 headlight bulbs with the clear fog lens. Headlights say bosch and dot. Which lights do i have? Thanks in advance.
1 - 8 of 13 Posts
Thanks for the link!! I finally got a chance to check it out. No power at either fog wiring connector at headlight housings. Pulled the lower dash and switch and found some interesting wiring. I took pics but didn't check before I put it back together and they didn't save apparently. There is custom wiring going to the switch, over to what looks like the ignition switch wiring, and down the drivers kick panel. But none was to the grey/white at switch connector. I didn't have time to follow it further and don't recall what colors they were wired to. Im going to have to pull it apart again. Where is that exterior lamp failure monitoring unit located? Also I have a lot more than 3 wires at my headlight switch unless im reading that diagram wrong?? Thanks again for the link. Lots of stuff Ill be needing in the near future!
See less See more
Had a chance to work on it today. Fixed the odometer and decided to pull dash apart and take pics. Also the fogs turn on and flash when the right blinker is turned on, headlights on or off. Whoever had this previous did some interesting wiring. The tails have wiring spliced as well that ill attach. And last week i ran some amp wires and found that right at passenger backseat floor where the factory loom comes thru under carpet there are 4 wires coming through cut. I forgot to take pics but can tear apart if needed but heres what i found. There are two power 12v, one direct and one fused, running all the way back to 2 wires there from engine bay. And then one wire is open and one is grounded back at floorboard?? All brake, tails and headlights work. Has no reverse lights.


See less See more
Was there ever a tow hitch attached to the car? Remote alarm?
Not that im aware of.
Look for holes that have or would have been drilled along the frame rails, either side of the spare tire well.. Any you pull it yards around?
Ok will do. No yards around me.
Im in grand island. I could probably figure it out but im not sure on the diagrams. Like previously stated my headlight switch has more wires than what is on diagrams and same goes for the tails so i dont know.
Finally getting back around to this. Am going to be ordering some depo euro headlights and bi xenon hid kit. I want to get this all working back to factory. I've been doing some research and can't determine if the euro tail lights have different wiring than us spec? I don't understand why my wiring is hacked up the way it is on tails. Also my factory wiring colors do not match the wiring diagrams found in the attached link and I have several more wires than any of the diagrams show for the headlight switch, on my switch. CD/W124/w124CD1/Program/ETM/ETM.pdf
1 - 8 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.