Does the car top box connection look anything like this? This is what you’d have on a 211 or 311 but may be the same terminal block. Made this for reference to wire a Cedes edge directly in without the blue box.

https://www.dropbox.com/s/9of93z1o61gvmlq/OPTIGUARD%20Edge%20Replacement%20%28Direct%20Wire%29.pdf?dl=0