Well first of all I'm new here. But my questions is, when doing my wiring is dang near the whole harness under hood swapped? I've done the swap before just went carbureted though. Wanting to do efi this time.
1987-1988 - Speed Density. All the speed density engine harnesses are interchangeable. Ford used a different computer in 86, but the engine harness is the same. The dash harness in the 86 is specific to that year car and will not work in the 87-93.
1989 - Mass Air and No Air Bag. One year only harness. This is the only car with mass air and no air bag. The dash harness is the same from 87-89 on all models, but the engine harness is specific to the 89. The 89 harness can be used in place of the stock 87-88 harness for anyone looking to do a mass air conversion.
1990-1992.5 - Mass Air with Air Bag. Fuel pump relay is under the drivers seat. The change here was made sometime in 92. All the dash harnesses for all models from 90-93 are interchangeable.
1992.5-1993 - Mass Air with Air Bag. Fuel pump relay is in the engine compartment. M12071C302 is this style engine harness. All the dash harnesses for all models from 90-93 are interchangeable.
1994-1995 - All the engine harnesses from the 94-95 V8 cars are interchangeable. All the dash harnesses from the 94-95 cars are interchangeable.