where would i find the pinouts for our headlight connector (2016 M4 coupe)?

I'm rebuilding a wrecked one and neither the replacemnt or the original, good side headlight are working properly. good side has DRL working and when i flip to high beams it clicks, plus yellow driving light works. "New" side (a used "working" one i bought off ebay) has yellow driving light and low beam, nothing else either side. checking voltages on the pins i cant make sense of it, get a lot of 2.5V on the smaller wires, 13v on one big one.