Battery Self-Discharge

Depending on the vehicle equipment, in addition to the natural self-discharge of the battery, various electrical devices draw current even when the vehicle is off. Therefore, on a vehicle that is not in use, the battery must be recharged at least once every 6 weeks.

If a parasitic current drain is suspected, check the electrical system as follows:

INSPECTION

1. Use a fully charged battery for the test.
2. Turn off all electrical loads, disconnect the clock, close the doors and hood. Close the luggage compartment lid.
3. Disconnect the ground cable from the battery.

* Disconnecting the battery erases stored diagnostic trouble codes. Before disconnecting the battery, refer to Battery Removal and Installation.

4. Set the ammeter to its highest range (measuring range 0 - 5 A). Connect the ammeter between the negative battery terminal (-) and the ground cable (-). Refer to the accompanying illustration.

* The check can also be performed with a test lamp. If the lamp connected between ground and the negative battery terminal does not light up, it is necessary to use an ammeter.

5. Switch from the ampere range to the milliampere range until a reading appears on the meter (1 - 3 mA is sufficient).
6. Remove the fuses one at a time and disconnect the corresponding electrical circuits. If the ammeter reads zero when one of the circuits is disconnected, the source of the fault is located there. Possible causes include corroded or contaminated contacts, chafed electrical wires, and internal short circuits in components.

If no fault is found in the circuits protected by fuses, disconnect the wires from unprotected components, such as the ignition system, generator, and starter.

If the ammeter reads zero when one of the unprotected components is disconnected, repair or replace that component. If there is a current leak in the starter or ignition system, always check the ignition switch as well.

Connect the ground cable (-) to the battery.