SAM unit question! Help! Very weird w220

[dddooommm]

Good morning mbclub,

For years I have delt with faults with old Sam units such as w209 fog light issues to corrosion issues inside that just needed cleaning out.

However this is really puzzling me. It's not hard nowadays for anyone to do research with the access of the internet and through reputable sources but very confusing when they give you contradicting information for the same issue!

I bought my old man an w220 s500.
The side light L is not working. (Passenger)

(Prior to blaming the SAM I've Checked bulb resistance, wire loom & contacts, checked voltage to the bulb)

So common sense would say clean the left passenger SAM from corrosion - if still faulty then replace with another one.

HOWEVER- Benzworld are saying left Sam controls left side of the car (but also controls the RIGHT headlight). Right Sam controls right side of the car (but controls LEFT headlight).
-This apparently is to prevent total blackouts.

Mercedesmedic's awesome write up "what is a SAM Module" that we have all seen before is amazing but very generic to all SAM units. It specifies left Sam for left (including left front lights) right for right components (including right lights)

Before posting this I've looked on previous threads / posts from other mercs of this era with similar faults but no definitive answer.
Annoying when people just wave the white flag and give their pride and joy to the dealer so we never get an answer.

Anyone else experienced or know anything else about this ?

Best regards

 

[dddooommm]

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[dddooommm]

Attached is
Mercedes medic & benzworld info on SAM units. Which one is correct about what side Sam the left (U.k. Passenger) headlight is controlled by?

 

[brucemillar]

On my W203 C55 Wagon. Both front sidelights were barely operating, receiving a voltage of 2vdc at the bulb holder. Everything else was fine, just two, very dim, front sidelights, that both had a low 2vdc supply. That was a front SAM (I believe there is only one SAM each end on the W203?)

What I was told (this may be just made up) is "If it is listed as "electronic" in the fuse layout - so it has no fuse! Then it is likely, SAM controlled"

 

[dddooommm]

Thanks for the reply Bruce,

The c class do have two Sam units but the S class w220 have 3!

The w220 have two under the bonnet then one under the rear seat bench.

Yeah electronic fuse is directly related to the Sam I'm just trying to work out which of the 3 are having the fault.

Best regards