A few weeks ago, I started a thread explaining how to tell if there is current drain when the car is shut off without having to remove the battery cable. All you need to do is measure the voltage drop across the negative battery cable with a millivolt meter. Most DMMs have an "mV" range and 300mV or less should do fine. On my old Datsun, I get a reading of "0" with everything off and a reading of .8mV when the interior light is on. Obviously using an ammeter in series will give you more accurate readings, but Apial tried it at my suggestion and blew out the fuse in his meter.
The botom line is, the current drain on standby should only be a few milliamps at most, just enough to hold the memory for the radio and power the alarm. Look at the small battery in your computer. It will hold the CMOS settings for years, so you shouldn't need several amps to keep the ECU settings intact. |