Use a charged battery to test.
Set the ammeter to the highest measurement range (0-5 mA and 0-5 A). Disconnect the ground wire from the battery.
Attention! As a result, the operating parameters are erased from the memory of the electronic injection control unit, and the key code of the anti-theft device and the set radio station frequencies are erased from the radio memory. Therefore, before disconnecting the battery, read the instructions to "Removing and installing the battery".
Connect an ammeter between the negative battery terminal and the wire connecting the terminal to the vehicle ground.
Attention! You can also check with a test lamp. If the lamp does not light when connected between the ground wire and the negative terminal of the battery, use an ammeter just in case.
Turn off all consumers, including clocks and other long-term connected devices, close the doors.
Switch from the A-range to the mA-ranges until the ammeter readings can be read (1-3 mA are considered acceptable).
Break the electrical circuits of various current consumers by removing their fuses. If the ammeter readings drop to zero when removing one of the fuses of an electrical circuit, then there is a fault in this circuit. The cause of the fault (current leakage) may be: corrosion and contamination of contacts, frayed electrical wires, internal short circuit in the unit.
If no fault is detected in the fuse-protected electrical circuits, disconnect the wires of the units not protected by fuses. These include: generator, starter, ignition device.
If the ammeter reading drops to zero when one of these units is disconnected, the corresponding unit must be repaired or replaced. If there is a current leak in the starter or ignition unit, always also check the ignition/starter switch according to the wiring diagram.
Connect the ground (-) wire to the battery.
Set the current time on the clock.
Enter the anti-theft code into the radio memory.
[The text of the article was copied from the website: Fordbook.ru]