My 7 opto board seems to have about 0.4V DC between J3-1 and J3-3. I think this is the source of my switch issues. I can't find anything in the manual or schematics that ties J3 of the 7 opto board back to something on the power board. Can anyone tell me what connector(s) on the power board (assuming power comes direct from there) provide the 12V to J3 of the 7 opto?
Solution:
The 12V and ground wires were pulled out of connectors in the backbox. Took an educated guess that I could wire them in to J118 with like colored wires that were supplying the correct voltage, and it was correct.