s12/ca18det 3 plugs issue

[krazy skwerel]

Ok so i have read and read keith's wiring guide and I am still confused on what i do with the three pulgs. The wiring harnessi am using was previously modded so that it worked in a 240sx. Basically I am trying to figure out if I had the original 3 would i just plug them in to the existing or does it not plug into the s12 harness at all and i wire the "3 plugs" from the ca18det harness into the relays and call it a day. i know this seems dumb but when i swapped this motor into my s13 the wiring was super strait forward as opposed to the s12.
Post Merge
never mind i am pretty sure i found my answer. Just ignore the plugs on the s12 harness completely