Alternator Voltage Reading Level

Hi All! I'm creating a club level wiring harness for my 2013 BMW 135i, but i've seen to run into a bit of a roadblock. Most of the harness documentation is completed - besides this one issue, where I don't know how I can get the OEM alternator to read the voltage level of the battery. This is used to determine how much voltage the alternator sends out in real time, but the OEM alternator seems to be based on running with a BSD line (Bit Serial Data) - I believe BMW specific.

I don't believe I can access this line, since I believe it's encrypted, so my current plan is I would leave the alternator voltage level reading sensor unplugged, and just let me output the maximum voltage. I'm not sure that this is the best idea though, as I don't want to possibly risk overloading actuators and some sensors. Does anyone have any suggestions for how I can go about this? The aftermarket selection of alternators that fit this vehicle are pretty selective, and I'm not sure I would be able to fit a universal one without some fabrication.

Thanks Guys,

Michael

Where does the BSD line come from? Is it possible to leave whatever module (B895?, Dash?, ECU?) that sends that in the car to continue to function.

Assuming that's not possible, here are some options I would consider, in the order I would probably try them:

- Try the alternator with the BSD line disconnected -- what is the maximum voltage? If it's less than 15v, I would not worry, and just run it.

- Consider using a stand-alone voltage regulator, like vehicles used in the '70s and '80s. Something like this might work: https://www.summitracing.com/search/part-type/voltage-regulator-and-rectifiers?N=voltage-output%3A13-5-constant-volts&SortBy=Default&SortOrder=Ascending

- Fabricate a bracket and use a new-style single-wire alternator.