[mpumas]

I gather that you are referring to fuse #1 (10A) which provides power to the injector resistors and the injectors. (The ECU provides a ground signal to activate the injectors.) That fuse also provides power to the ECU. What is between the fuse and the injectors/ECU is the main relay. Therein lies a couple of resistors, relays and diodes. You might disconnect the main relay and see if the short goes away. If it is not in the main relay, the next place to look is the ECU. Keep us advised on what you find.