fr Mister C

hello!
I need guidance for a turn signal failure on a 1997 E300 td (model 98, VIN WDB2100251A513680). It only has 198,000km, has had decent maintenance, but hasn't really been driven much in recent years..., since I bought this car a month and a half ago, I have had no problems, just its indicators which work perfectly with the engine stopped, when starting, but go off after a few minutes or kilometers... as soon as I turn off the ignition, everything becomes ok again.
I have the maxiecu3, this one shows me the C1025 faults on the BAS ECU (I don't pay attention to it, from what I have read, the software is looking for a communication with the ESP... I only have ASR/PML and ABS), as well as fault B17555 (Since I cleaned the EIS and AIRBAG ECU sockets under the ashtray).
I'm going in circles, my fuses are ok, I hunted down bad grounds and connections (which solved other problems for me ).
Today, in my research, I am at the following point:

--> The indicators work at startup, then become faster/or flash more randomly, ending up not working at all after a short time (until I turn the ignition off and on again).
--> My idle battery is on average at 12.35v.
--> Charge regulator ok.
--> Fuses ok.
--> The warnings have no operating problems.
--> My indicators work without fuse 12(???) on the left of the steering wheel, and I only have 0.5 volts to go through there(?) If I remove the 41 on the SAM, they cut out.

When I lose my indicators, if I put on my night lights, the indicators work, but poorly. If I turn on the main lights, OR the high beams, they work normally. IF I turn on the ventilation, the faster I turn it on, the better the indicators work normally... basically you need a strong enough consumer for everything to return to normal...

In short, by reading everything and anything on the few forums dedicated to Mercedes, my problem is, I'm sure, "quite simple" but i get lost and no longer know where to look... Can anyone guide me, or have an idea about the problem?

Renaud

view of my type of car and options

ilove190evo

From my past experience, but may not apply to our beloved MB, check your ground point or wire.

When you load something as high amp as headlights or ventilation, things usually take the other route, which means those thing eat amp/voltage, things start to slow down. But in your case, it's the other way around so my first GUESS is the ground.

But even before that, have you scan the car? If it's electrical, it usually show up on the scanner. However in your case, may be wiring so it may not, but if you haven't, scan your car and stop guessing.

fr Mister C

This is exactly where I don't understand, because from my point of view it's more a problem of power supply rather than ground due to the fact that the stronger the consumer... best is the job of the turn signal
The car was scanned, and only these 2 fault codes came out. As said above, the sporadic C1025 code( CAN Communication BAS communication with ESP control unit faulty) is a problem reading my scan (my car does not have ESP) and I am looking for the second one, permanent B1755: Serial interface from K2 control module interupted. (my indicators were already working poorly before its appearance ) I don't have any others and no messages on the dashboard

Plutoe

my WAG is that you have a faulty 10/1 front SAM one of the chips is faulty and they are not replaceable-------also make sure the part numbers are compatible thru the use of MB EPC----all else is a FUYA

ilove190evo

Plutoe may be right. It's a different car, but on my 2004 Lincoln LS (which is long gone due to parts availability and numerous problem. It does make sense since car was basically reskin Jaguar. Electrical nightmare) , I had to replace one of the rear module to have right tail lights to work. The whole light assembly lost power. That was reverse, tail and brake lights. After I got used module (New one wasn't available), worked fine.

Just from my experience.

fr Mister C

I took some measurements this weekend, the bulb power supplies coming from the SAM being individual, I checked the resistances of the power supplies... So no worries at the front, connected or not to the calculator, on the other hand at the rear... no worries if disconnected from the SAM (infinite value) but 11 ohms on the right and left connectors if the harness is connected. By disconnecting all the other connectors 1 by 1 to try to isolate the sources... no change. The fault must indeed be located on the SAM, on the other hand I dismantled it, no traces of oxidation, no burnt circuit or component, maybe a short circuit at the socket but this one cannot be dismantled without risking breaking it. Taken for time, I did not go any further and put everything back together... but indeed, I think the fault is this damn calculator

Plutoe

wow thank goodness the problem was not why is the sky blue

fr Mister C

OK, well it failed... I believed it but no. I found a turn signal switch, a warning button, and the famous SAM... I exchanged it as in the order mentioned above with tests between each, the problem is still there I'll have to dig deeper.