5.0 Wiring Harness --- 87-95 Wiring Changes
87-95 Wiring Changes - There are several different harnesses Ford used on the 5 liter Mustangs. If you are doing a conversion or need a replacement harness, here are the differences in the harnesses by model year.
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. 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.