I took my car to the Mercedes Dealer in Birmingham for repair. The "check Engine Electronics" light came on and the code it was reading was for the Resonance Intake Valve. The valve below the RIV was replaced a few weeks ago and the CEL light kept coming on so I took it to the dealer. I was told they had to replace the RIV (as expected), but the CEL light came on after replacement and this is where my problems/concerns begin with questions I hope someone can help answer.
The mechanic at the dealer said there was a bad switch on the RIV and it needed replacement, so he did, and the CEL light came on again. I left it with the dealer and a week later, they said I needed an "alternator and a battery", that my battery was completely dead and would not take a charge. I brought a new battery to the dealer and they put it in but said "something was draining the battery". I went home and a few hours later, the new battery was completely dead. I took the car in to have the dealer fix the problem that did not exist before I took in the car. The mechanic did several electrical tests and I believe he shorted my electrical system.
My electrical problems are still arising as my now bulbs on the display are blown, I am getting a "Lamp Defective" that is intermittent, my golw plug light is coming on and off intermittently, yesterday, my radio wouldn't work, but an hour later, no problem, and the cabin light did not work today. Each time, I get a warning light indicating a new issue, electronically related.
What else can I expect? I don't want to nickel and dime the dealer to death, but they were responsible for shorting out the system. Can anyone please provide me with some resolve? comments? future concerns? advise. Please help.

 

I doubt if they shorted the system. Perhaps there is a bad connector or one that is not correctly installed. I suggest that you let them have the car as long as it takes to fix it and ask them to provide you a loaner.