near to my relays on the drivers side bulkhead area, i do have this black plug with the blk/yel r/yel (pretty sure thats it) wires going to it, pretty heavy duty lookin wires too, so figured they wud b powering something substantial

is this where the sub-loom joins the main loom then yeh?

if so, i can just try and pick up a sub loom off someone with a loom removed i guess, good times