These drawings explain how the injectors are connected for each injector driver. The amount of connections will vary with engine size. (See specific drawings for your application.)

Batch & Split Batch Wiring
With this method you always combine 2 injectors in Parallel. In this drawing A1 is on cylinder 1 and A2 is on the cylinder that moves with it.

Batch & Split Sequential Wiring with Dual injectors
With this method you still combine 2 drivers in parallel. The electronic relay will split the power from getting to the dual injectors. The ECU will switch the electronic relay on with a positive signal from one of the positive drivers reserved for this function. Note: Make sure that the driver can take the combined current for the 4 injectors. Mercury2 can handle 6 Amp per driver. A diode large enough must be wired-in for each bank from the electronic relay. This will prevent power feedback from the injector drivers when the electronic relay is off. For 2 high impedance injectors the diode must be 3A or higher. In this drawing A1 & A2 is the primary injector and A3 & A4 is the dual injectors. A1 & A3 is on cylinder 1 and A2 & A4 is on the cylinder that moves with it.

Full Sequential Wiring
With this method only one injector is connected per driver.

Full Sequential Wiring with Dual injectors
The electronic relay will split the power from getting to the dual injectors. The ECU will switch the electronic relay on with a positive signal from one of the positive drivers reserved for this function. Some applications have enough drivers and then the dual drivers are connected (as above) onto its own driver. No electronic relay will be required. A diode large enough must be wired in for each injector from the electronic relay. This will prevent power feedback from the injector drivers when the electronic relay is off. For high impedance injectors the diode must be 3A or higher. In this drawing A1 is the primary injector and A2 is the dual injectors.