I have a couple of mystery boxes that I was hoping someone could identify
and point me to the schematic that this was wired up with.
here are the two boxes
The first one looks like some type of a 2-wire data bus spliter. Could be CAN-BUS, but I would expect to see at least a ground wire as well. Possibly an RS485 2-wire setup.. If you could get a picture of the lettering on the chips that are visible on the board, it would go a long way to helping to identify the box's function.
On the second box, you would need to share a picture of what's inside the box including any chip labeling...