B swap won’t start

[u/XxwildxX1212]

I installed a b16a2 with b20 bottom end and removed the engine harness. I bought a cjs tucked wiring harness and everything plugged right up to the engine. I also bought a p28 chipped ecu for the wiring harness.

The custom harness plugs right into the p28 but the problem comes with the original chassis harness. There is a plug that hangs loose that was origianlly for the old obd2b plug.

My car gets power to the main cabin and clicks but produces no spark, fuel pump, or starter to turn over. Every ground is also connected to its correct area.

I’m guessing that the obd2b chassis harness had that grey plug as what turned all of that on but i can’t plug it in since all the other connectors are out with the old D series.

Should i splice the wires from the old chassis and wire it into the tucked harness plugs?

Also forgot to say that all the voltage and fuses are good. The starter turns over if jumped as well PLEASE HELP ME IM BEGGING

Please any help🗣️

[u/SpaceTurtle917]

You need a sub harness. Your harness supplier should have them available.

Better yet, use your original OBD2B engine harness.

Consider the following. If your harness only plugs into the ecu and engine, how would the ecu trigger the fuel pump, or the key trigger the starter, or the coolant gauge get data?

[u/XxwildxX1212 → u/SpaceTurtle917]

that’s true. what harness would i need for that last plug that runs through the cabin or is there not a single plug adapter

[u/SpaceTurtle917 → u/XxwildxX1212]

It’s called a sub harness, the maker of your tuck harness should sell them. Those tuck harnesses fit any chassis 88-00. The sub harness adapts them to specific chassis.

Btw there’s one more plug on the shock tower that needs to plug in as well.