OEM relay panel function? (1 Viewer)

[JohnnyFish]

I have a general automotive knowledge question that I hope the collective can help me with. I grabbed this relay/fuse panel out of a Nissan Altima to use for lights and accessories in my 96 LX450. I’ve reverse engineered the pin out for all 11 relays but for one side of the coil on each one. There’s no obvious way to activate any of the coils (at least the big dpdt ones) with the attached wiring.
The heavy gauge wires, when energized, activate an internal relay in the lower left. That seems like the key, but I haven’t figured it out. Assuming this is a common OEM design, anybody have guidance?

 

[mudgudgeon]

Do the relays all share a common ground?

I've just done a little project and made a circuit board to mount relays. They all share a ground, and use a single wire from the switch.

 

[mudgudgeon]

Do the relays all share a common ground?

I've just done a little project and made a circuit board to mount relays. They all share a ground, and use a single wire from the switch.

Could also have a common power feed and be activated by grounding the other side

 

[JohnnyFish]

I got it apart and found that what I have here is actually the ECU. So, if I want to continue to try to repurpose this as a simple fuse and relay board it’ll take some time and solder.