MikeMazz

Hello - for clarity on a scale of 1-10, I'm about a level 3 mechanic so please excuse my terminology.
I have a 2008 ml550. The left front low beam headlight does not work; I've changed the bulb and headlight assembly and still doesn't work. However the high beam does work so I know it's getting power. Occasionally it will work randomly as I'm driving and then go off. The same is with the left rear brake light. I've replaced the bulb and it will work for a week or so and then stop working. Any help is appreciated.

kombifan

Well if it's both front and rear its not an issue with the headlight but probably issue with the Sam.

Major Dundee could probably inform you more on likely issues if you provide the vin,

But have e you looked at water intrusion in the front and rear Sam?

These are known issues.

MikeMazz

Thank you. I will look at the front and rear SAM and also provide the vin. Who is Major Dundee and how do I send the vin to him?

kombifan

This guy. https://mbworld.org/forums/members/2...aj-dundee.html

Check for water intrusion for the front Sam. It is in the front passenger footwell. Leaks appear through the sunroof or a spilt drink.

The rear Sam leaks are caused by faulty seals of the rear taillight.

Maj. Dundee

Give me some time to look into this.

Maj. Dundee

Do you have a scanner that can read codes in all of your 25 or so modules?

Did the front and rear lighting issues occur at the same time?

When the brake light problem occurs, does the auxiliary brake light come on?

Remove the left tail lamp and then remove the brake light bulb and see if there is a burn mark on the contact strip. If so you must clean & solder the burn mark to make it level again.

While you have the tail lamp out, is the seal affixed to the lamp? If so you must replace both of them as they were incorrectly installed at the assembly plant, as they should have been installed on the body opening.

The headlamp issue will be addressed after this issue.

Please answer all questions.

Maj. Dundee

Please UPDATE YOUR PROFILE in USER CP to include the year and where you live.

kino1161

Maj Dundee, do you have to clean and solder the burn mark?

Maj. Dundee

What burn mark and where? Post a photo.

kino1161

I am not able to post a photo at this time but the actual frame of the light where the bulb socket screws in has a small "arc mark" (for a lack of better terms). In another post on this site, the member identified the burn mark and said they used a dremel to get rid of the "burn" mark.

Maj. Dundee

So then try to remove it.

kino1161

I re-attached the harness the way as explained above. A few years ago I attached it the "splicing wires" way. It seems to be working fine now.....again.