Ok I’m swapping a first gen small block into my 1999 s10 ls. This truck came as a 2.2 and automatic transmission. I’m in need of some help with the wiring. I want to remove the ecm and efi harness. I still need the truck to start from the key and the headlights/taillights work on the truck. I added a photo of a plug in the harness that i need help with. This plug hook's in to the ecm/efi harness what all does it work in the truck? This harness also runs back to the relay center under the hood on the ecm side. All help is welcome thanks.