Install on ammeter (with measuring range 0-5 mA and 0-5 A) the highest measurement limit. Connect an ammeter between the negative battery terminal and ground cable. Connect the positive wire of the ammeter to the positive terminal of the battery, and the negative wire of the ammeter to the negative terminal of the battery.
Turn off all electrical consumers, close all doors and trunk, turn off the engine compartment light.
Switch the ammeter measurement limit downward until any reading appears (allowable value is 1-3mA). When removing fuses one by one from the fuse box, open all electrical circuits in sequence. If, when one of the circuits opens, the readings drop to 0, then the source of the malfunction should be looked for in this circuit. Possible malfunctions: corroded or dirty contacts of electrical connectors, frayed wires, internal short circuit in electrical equipment elements.
If no fault is found in the fused circuits, disconnect the wires from the non-fused devices: generator, starter, ignition system components.
If the ammeter reading drops to 0 when one of the unprotected circuits is disconnected, repair or replace the appropriate element. In the event of current leakage in the starter or ignition system, always check (in accordance with the scheme) ignition and starter switch.