For the BCM there are a lot of relay controls but I am not going to make use of them at this point.
There are a Ground and Battery connection which I will put to ground and +12 accordingly.
There are a number of Serial Data Signals. Note this vehicle is a J1850VPW so there is only one actual wire but at this BCM there are a total of 3 different serial data outputs.
They are listed as:
Diagnostic to Body module - Assuming this is the one that goes to the ODBII connector.
Serial Data Signal - Assuming this is the main data line going to the rest of the vehicle.
Serial Data Signal (On another connector) secondary . Guessing this goes to specific modules
Not sure why there are 3 different serial data outputs. Guessing that they should all be the same data? Without actually tying into them I guess I won’t know for sure. I can try sorting it out from the factory manual but not sure if the wiring is all listed.
There also is an Ignition 1 and Ignition 3 on this as well.
Should I assume I just put these to +12 volts?
There is also a reference voltage feed which I am not sure what it is for without tracing it down.
So for BCM it looks like the Battery, ignition 1 and ignition 3 all go to +12?