So recently I replaced my fuel sending unit due to someone patching a leak with jb weld. The car ran good on the test drive I took it for but after I parked it and left it for a few hours and came back it wouldn't start at all. I ended up replacing the fuel pump assuming it was the issue and still had the no crank issue but ended up finding out it was tampering with my rear Sam that's causing my issues.in place of my fuel pump relay was a wire that
Traced back to being hotwired to a fuse that had these three wires spliced onto it. I'm trying to figure out where these three wires go to on the car to see if I can get the entire harness replaced and need help if anyone's knows.

 

The last Ytube video I watched showed a Mercedes master tech proposing a fix like that to splice the p/s headlamp into the d/s circuit to avoid replacing the SAM.

He meticulously went through and determined it would not be a hack that would comprise the system and advised his customer of the same.

Is there any way you could reach out to the previous owner to inquire about it knowing your looking for info, not retribution?

 

The alterations to your rear SAM wiring likely caused disruptions in the vehicle's electrical system, which can prevent the engine from cranking. Hotwiring the fuel pump relay and splicing additional wires may have introduced voltage irregularities or short circuits that compromise essential functions managed by the SAM, such as the starter circuit or ignition control. Additionally, these modifications might have interfered with communication between the SAM and other control modules, leading to a no-crank condition. Damaged wiring harnesses or blown fuses resulting from improper splicing could also be contributing factors, disrupting the necessary power flow for starting the engine. I would recommend running a full system scan to identify any fault codes related to the SAM and other affected control modules. There should be fault codes stored that can help pinpoint the exact issues caused by the wiring modifications. You might need to take the car to a mechanic for a comprehensive diagnosis, but if you prefer to troubleshoot it yourself, the youcanic full system scanner is excellent for diagnosing all systems. Just ensure you use a full system scanner, as some tools might not read all vehicle systems and could miss important codes.

 

What he said …

 

hey is there any way have pictures of where the wires that were cut went and how they were wired to the fuse. I’m about to have to do the same thing