93 Foxbody 2.3 auto V8 Swap need HELP!

If the car is a 93 I would honestly just sell the 89 wiring. They are easy to sell because allot of people need them for conversions for there 89 and below cars or just to swap to mass air. Toss that money towards the 93 main harness that you need. Install that harness in car, plug in your ECM and your good to move on to the next issue.

When purchasing a 93 harness it's easy to tell them apart from other fox harnesses. Look for a redish brown round large connector (dash/body harness connection) and two relays by the mass air plug

You can also use some 92 model year harnesses as well as they are the same as the 93 model. Only the later model year 92 harnesses are usable with 93. Early to mid year 92 harnesses you do not want for your 93. They do have the same big round red dash/body connection that you need but there fuel pump relay isn't by the maf. It's further in the wiring and places it under the driver seat. So avoid that one, just look for the big round redish brown/red plug and two relays by the mass air plug.

You will also need a 90-93 Manual o2 harness or just repin your current harness. If you don't you'll damage your ECM.