Once the male connectors are connected to the wiring harness, it is ready to be installed to the vehicle. Do not change the order of original connectors! eFlexFuel injector wires can be in any order. The connector pair with double red wires (+12V) needs to be always connected so that eFlexFuel gets its operating voltage.
If the engine is equipped with double injectors per one cylinder (4 cylinders -> 8 injectors), the first injector wire must be connected to the so-called primary injector (located nearest to the cylinder head). If the first injector wire is connected to secondary injector, eFlexFuel will not work.