I have a 2005 Corolla CE with manual transmission. About one month ago the car would not start, and the battery was discharged to about 8.5V. Car had been not running for a couple of days but nothing was left on.
Since the battery was under warranty, I replaced it. Charging system is OK (about 14V, and this problem only happens when the car sits for a couple of days).
The only issue I noticed was that the radio stayed on when the ignition was off (though the clock display did go out), but maybe it is not related. Anyway I turned off the radio.
For about 2 weeks all was well, every day or two I checked the battery voltage and it was OK.
Then a couple of days ago it was discharged again (about 8.5V). So first I charged the battery and the voltage has remained about 12.7V with nothing connected.
So it seems like some intermittent electrical drain is happening. A couple of times when I connect an ammeter in line with the battery (with everything off), the current measures about .2 amp. But a couple of other times .7 amp. However I don't know if this kind of checking has any validity.
So I am looking for some way to find out what is happening (since it is intermittent), or if there are any known problems like this. I might pull the audio system fuse in case it is involved (it is a stock system) but that is all I figured so far.
And if checking the current at the battery is valid, can I use this to try to find the problem?