jim_johnstone

I took the left side dip bulb out of my 2006 ML350 (6 weeks into ownership) to check the bulb type as the performance is very poor. Halogen bulbs by the way. Unfortunately it looks like I've opened a can of worms. The yellow wire which I presume comes from the SAM was disconnected from the bulb holder. Instead was a new wire roughly spliced into the holder and partially covered by some insulating tape (really bad job).

I'm hoping someone can help me in my thinking. I presume something in the left SAM has failed, and rather than pay money for a proper fix the previous owner is running a live feed from the right headlight dip. Now, I'm wondering if the poor output is because the right SAM is now having to power 2 lights and is not capable of supplying the extra load required, and is there something in the left SAM that can be repaired. It seems like a lot of expense if the SAM has to be replaced for just the dipped beam.

I'm a bit too old school to understand SAMs, but I suppose a workaround would be to install a relay in the new circuit with a new live feed from the fuse box, and use the power from the right dip beam to trigger the relay.

Has anyone else had this problem, and what is the recommended fix.