Welcome to the thread, spud06! What you will need is a Chinese clone of the Mercedes Star Diagnostic System (SDS) hardware and software. Specifically, and this is very important, you need a version of the SDS software that was built before Sept 2015. The reason is that from that point on SDS no longer included HHTWin, the Windows emulation of the old Hand Held Tester (HHT) that was originally used by MB techs to diagnose our cars, and is necessary to diagnose them. The software is usually shipped on a SSD for installation on specific, discontinued laptop computer models. For instance, my software was delivered on a SSD for a Dell Latitude D630 laptop PC, of which I was able to purchase a refurbished unit on amazon for small money. On the hardware side, you will need a C3 (wired) SDS multiplexer box with a cable terminated by the MB 38-pin connector to plug into your car's diagnostic port. You probably know by now that your car does not have an OBD2 port. You may be able to buy the hardware and software separately, or bundled into a complete kit that includes the PC to run the software. I bought my software, hardware, and PC separately since I could not find a bundle that included the pre-9/2015 software. I bought the hardware and software on aliexpress (Chinese equivalent of amazon). Don't skimp on the hardware quality - purchase one of the more expensive models to avoid configuration issues. I found advice on another thread to buy a model with the word "super" in it, and that is what I did, and I haven't had any issues whatsoever. Good luck and welcome to the R129 club.I've read this entire thread and you guys are amazing! I just got a 95 SL600 with 113K miles. I have 3 wiring harnesses, hydro spheres,, and maybe a MAF to replace, but that all sounds simple compared to what you guys are dealing with. What equipment do use for diagnostics and where should I get it? There seems to be something available from Hong Kong and then StarTeckInfo. How do they relate? What do I need? Thanks.
Edit: Corrected year of deletion of HHTWin from SDS software and my laptop model.