Okay, so I LOVE the W220s, but I was sorta tricked into buying my most recent one and it has a bit of issues I have to resolve, debating if it’s worth keeping. Biggest issue, the electronics are…. Wild: getting codes for all 3 SAM modules failing (with the obvious symptoms as well haha), the head unit was swapped for an aftermarket (which would normally be better for me) but when the PO did it I’m guessing they didn’t pay much attention and as a result not all of the speakers work and none at full capacity, and the mechanic he took it to (who sold it to me 🤦🏿‍♂️) rigged the high beams to work whenever the car was turned on since the lights were going crazy before, but as a result killed several other electronics (window switches no longer work on any door, sunroof controls inop, steering wheel adjuster inop, door trim lights inop, lowbeams inop, reverse lights inop, rear flashers inop as well as marker lights, gas gauge inop, headlight switch inop). I was wanting to just replace the SAM modules since there was obvious signs of corrosion and failure, but instead of going with my idea this mechanic decided it was better to rig up the lights after failing to clean them. Keep in mind most of those electronics I just mentioned worked before he did that, but no wires from the actual SAM modules or there connectors themselves are cut (he tapped into the high beams through a fuse). I’m not concerned into suing or anything, really just trying to move on and up from the situation, think if I go back with my idea and change the modules I’ll be alright?

 

Sounds like you have your work cut out for you. Do you like the car enough to endlessly work your a$$ off on it? Electrical gremlins suck unless you're pretty sharp with troubleshooting, not to mention whatever else you find along the way.

 

You would greatly improve your chances of getting useful info if you told us the exact model, year and market, 4Matic or not, etc., plus exactly what you know is physically wrong with the car.

 

Run Away from this water-damaged beast. Electrical gremlins are SO DIFFICULT to find and fix. These cars are very complex with various SAMS and relays placed throughout the vehicle, seemingly in no particular fashion. While You May be lucky and have few issues, the odds are not in your favor. There are many of these cars 'totaled' by 2nd, third, and still subsequent owners for 'electrical gremlins. The 'hard parts' are generally very reliable, but the OLD electrical relays and modules do fail and cause very expensive parts replacement. It seems as if "Good Manufacturing Practices" went out the window for a few years as Daimler began 'outsourcing systems work' and leaving their engineers with the task or 'integrating' the stuff into the cars. Often, the first time the systems were tried (integrated) was the first production cars.