Current Leakage Test

Current leakage refers to power being drained from battery with ignition switch off. Battery drain should not exceed 20mA (.020 amps). Typical draw is 15mA. 10mA are needed to supply electronic control unit, digital clock and electronically tuned radio memory.

1. Check to ensure no accessories are on. Excessive battery drain can be caused by items left on, such as reading lights, dome light and trunk light.
2. Excessive battery drain can also be caused by bad alternator diodes, shorted stator windings, shorted regulator and intermittent short in wiring.
3. Using an ammeter capable of sustaining greater than 10 amps, connect ammeter in series between positive battery cable and positive battery post. If current leakage is less than 10 amps, connect an ammeter set at 10-amp range in series between positive battery cable and positive battery post.
4. If voltage draw is less than one amp, connect an ammeter set at 100mA range in series between positive battery cable and positive battery post.
5. Main power branches can be isolated by removing one lead at a time from 100-amp main fuse. Further isolation can be located by removing circuit breakers and fuses.
6. Ammeter reading will drop once current leakage is found. Repair as necessary.