This harness was designed for systems with up to 4 injectors, 4 smart coils and a FuelTech Wideband Nano O2 with Bosch LSU 4.2 sensor. It's setup to run semi-sequential or multipoint injection and wasted spark. It is already wired for FuelTech Peak and Hold drivers when using 4 low impedance injectors. When using high impedance injectors, a Peak and Hold driver is not needed and in this case, only a bypass connector (jumper wires sold separately) is required. There are 3 separate relays to power the whole system, separating the injectors and coils from the electronics. To activate coils and injectors relays the Blue#6 output must be configured as Fuel pump or RPM activation.
*This is only the A harness which is all the FT450 requires.
If you are using an FT550 and want to use all of the extra inputs & outputs, you will need to purchase the B expansion harness as well.