I own a 2008 e350 base and on the dash I have seen messages about the Right Park Lamp and Left Licences place lamp, both I ignored because it just didn't bother me, plus I've checked them off and on and sometimes they work sometimes they don't. However, the other day a "Right Low Beam" message came on as well and the larger passenger low beam wasn't working, but the smaller one was working, and both driver side lamps were working.

I bought a new low beam bulb H7 and installed it this morning, both driver and passenger lights worked. Later in the day around twilight I had to drive my brother home and when I started the car I checked the headlamps just to make sure. What I noticed is the larger passenger low beam was working, the one I changed, but the smaller one next to it wasn't and of course both lamps on the driver side were working. This had me confused.

When we got to his house I turned off the car and back on to check the lights and when I turned the car back on, the larger passenger low beam wasn't working, but the smaller one was working. More confusion

By this time its dark so I drove home with both driver side headlights working but only the smaller passenger side working with the larger passenger low beam not working.

Luckily I wasn't pulled over but I didn't have far to drive. Once I entered my neighborhood I stopped with the car running, and I switched the interior headlight switch from Auto - to - On, and all of a sudden all four lights were working. So I continued to park at home and with the car on I once again, using the headlight switch, turned the headlights from On - to - Off - to then - Auto, and when I did, both passenger side headlights didn't work.

I turned off the car, went inside, came out 15 minutes later, turned on the car and again both passenger side headlights, large and small, don't work.

I called a friend who is a mechanic but not necessarily Mercedes, I told him this same thing here, and he suspected and I may have a bad Headlight Switch. I asked if it could be a fuse and he doesn't think a fuse would act that way. If a fuse went out there wouldn't be this on and off ordeal between both lights that occurred.

I've checked this message board and I have come to gather maybe it is the Head Light Switch and or a Rely or Ballast?

Anyways I am not mechanically inclined and curious if anyone may know what it could be and/or how much it'll probably cost me taking it to a shop not the dealership

 

Sounds as though the grounds inside is chaffed and needs replaced or fixed. I would remove the housing and open the back - check the wiring inside for breaks as well as the wiring outside to see if it's loose or broken.

 

I initial suspected it had to do with the wiring. Its relativity new housing, aftermarket, been on for 9 months prior, both sides were done - thinking the wiring from the car that connects to the housing is loose or broken. I am not mechanically inclined so idk how to approach this problem.

 

If you search the old threads, the sockets on the parking lamps rust out pretty easily. I've changed the bulbs in mine a few times but eventually had to change the socket as water seems to get inside and the socket rusts out. Socket is about $15. For the license plate lamp, it's well know that the bundle of wires in the trunk get frayed and typically one of the things that goes out is the license plate lamp.

Anyway, headlamp switch sounds like a good guess or check the wiring to make sure it didn't get rusted out also. You could also just give up on auto and just remember to turn the headlights on manually. I had a similar problem on a different car brand, but in that instance, it was a bad relay on a control board that would have cost several hundred so I just go used to turning on the headlights the old fashioned way instead of spending the several hundred to fix it.

 

I pulled the car into the garage this morning and the auto switch is still on and my passenger lights came on, however, I got a notification that my passenger side blinker doesn't work..... so everything is coming for the right passenger side... and its a hit or miss on what might work it seems, whether its the blinker, the bigger headlamp or the smaller lamp...