OP -- any updates on this? I have the same model and bought the parts that you suggested that you needed. I think that I will take off the panels this weekend, hopefully, I don't need anything additional.
Ok, I forgot to mention that I am a complete novice when it comes to electrical stuff (outside of safety). I'll borrow my friend's multimeter and see what I come up with. Does anyone have a pic with a clear view of the pigtails and grounds connected to the El Grande?
Welp, tried today on my 2013 SL. All ai managed to do was blow three fuses(wife is pissed that I ran out of daylight and now we have NO horn lol). I'm not sure what I'm doing wrong -- I fashioned two pigtails (power to black stock connector with white wire, and ground to brown stock connector...
Based on your post, I bought all of these parts(except for screws) for my 2013 SL. Is the body to hatch harness the last harness before the camera? I plan on installing this weekend.
I've tried sifting through this thread to see what exactly I need for my 2013 SL (installing FIAAM El Grande). I tried it using the instructions way back on the first page, but after removing the panel and coolant tank that I had instructions for the wrong model year -- so I put it back together...