Hello everyone! Sorry to make this my first post here, but I found a lot of posts on here from very knowledgeable people and figured I'd try to get my current problem solved.

First of all, I tried to make a crudely edited video summary of my situation in case anyone is interested here: https://www.youtube.com/watch?v=JUv-KTYq7fA This is a 17 minute video, the first 7 minutes is mechanical stuff where the last 10 is me messing around with STAR.

So I bought myself a 2002 E320 a few months ago and it was driving fine. A little over a month ago the car was stuck in hard limp home mode so I decided to invest in a STAR system to clear the transmission codes and drive it to my uncle's shop to change the common failure points, the conductor plate and that plug housing. Everything went well, so I replaced off the fluids and tried to start her up to no avail. I knew the battery was weak, so I tried starting it with various battery packs attached and was able to get it to start some times, and some times not. Not wanting to take up my uncle's shop for much longer, the next time I was able to start the car I drove it home thinking the battery must be dead. I replaced the battery the next day however and I still can't get the car started. Additional jump start packs don't work either and I actually haven't been able to start the car for about a month now.

Things I have tried so far:

Tried to start in neutral and park, same result. The gear position sensor on the right display does show the proper gear though, and the key turns to all positions as well as unlocks and locks all doors with full functionality.

Tested all the fuses in the rear by the battery, on the front left drivers side, and on the k40 module.

Tested the starter relay and it showed about 74 ohms.

Crossed terminals where the starter relay plugs in to test starter, starter turns over endlessly when key is in accessory position (you can see this in the video).

I activated the alarm and disabled it with my key, still no start.

I have tried starting after pressing the anti tow button, but I don't know if it is activating properly (also in video)

I tried disabling the ESP via the instrument cluster, although I did't actually see anything change when I did it. I followed the instructions mentioned here: (How to switch off ESP, ABS & BAS systems - Mercedes-Benz Forum) but I was unable to cycle through the menus described there, and I am not getting any warnings about esp being off on the cluster. I don't think I really changed anything.

What I have seen with STAR:

Currently the only faults shown after a recent clear is an audio fault about the DTB buss, prior to this I was showing faults for the ESP for a steering angle sensor, and tele aide error for an open circuit. I have tried messing around with a few other options, but I am not too familiar with star. When I attempt to do an "Initial startup" under the motor electronics section, it completes the coding process but stops and says "drive authorization immobilized" and proceeds to abort the process. This is the only indication that I have been able to find with star that I have a problem.

I'm really hoping I am just overlooking something really simple, but I am seriously stumped on how to fix this. I don't understand why this has occurred when I changed out the conductor plate, the worst I figured could happen is that the car would go back in to limp home mode. I'm hoping I can get some ideas from the wonderful people here.