- remove the negative terminal from the battery, connect the universal tester wire between the negative terminal of the battery and «weight». If the tester shows the presence of current, there is a faulty consumer in the circuit;
- reconnect the negative terminal, open the fuse box and remove one fuse. Connect the tester wires to the fuse contacts. If the device does not show current, the circuit of this consumer is in order. A small amount of current is acceptable. Devices such as clocks, radios or alarms constantly draw power from the battery. However, the current in their circuit is much lower than that of the faulty device;
- continue measurements on the fuse box until the device is identified, in the circuit of which there is a large current. The fuse table in the instruction manual will help you determine which device is connected through a given fuse;
- disconnect the suspect consumer and measure the current. If the tester no longer shows current, a faulty device has been detected.