Current Leakage Test

CAUTION: Before connecting ammeter, ensure all accessories are off and doors are closed. Failure to ensure accessories are off could result in ammeter damage.

Current leakage refers to voltage that is slowly drained from battery with ignition off. Battery drain should not exceed 20mA (.020 amps). About 20mA are needed to supply memories of electronic control unit, digital clock and electronically tuned radio.
Ensure ignition and all accessories are off. Excessive battery drain can be caused by items left on, such as reading lights, dome light, glove box and trunk light. Excessive battery drain can also be caused by bad alternator diodes, shorted stator windings, shorted regulator and intermittent short in wiring.
First, use an ammeter capable of indicating greater than 10 amps. Connect ammeter in series between positive battery cable and positive battery post. Note amperage draw. If amperage draw is less than 10 amps, set ammeter at 10-amp range. If amperage draw is greater than one amp, pin down problem area by disconnecting possible large amperage drains first, such as alternator, starter and ECU.
If amperage draw is less than one amp, set ammeter to 100mA range. Isolate main voltage branches by disconnecting or removing one fusible link at a time from main power source or fuse panel. Further isolate problem by removing circuit breakers and fuses. Ammeter reading will drop when amperage draw (current leakage) area is located. Repair as necessary.