Toyota Repair: 2000 Toyota Corolla, toyota corolla, negative battery

Question
Hi,

I have a 2000 Toyota Corolla. Lately the battery has been
draining when the car sits unused for a period of time. I have
checked carefully and there are no lights on, the doors are no
ajar, the radio is off, and nothing obvious has been left on.

The battery is fine and holds a charge.
If I unplug the battery terminals while the car sits, it works fine
when I re-attach the battery and start the car.

Obviously there is a drain on the battery somewhere. Any ideas?

T

Answer
The only way to check to see if there is a current draw with everything turned off is to connect an ammeter in series with the negative battery terminal, you can use a digital VOM, disconnect the negative battery terminal and connect the meter between the terminal and the negative post to read the current draw, it should be less than 5 milliamps.  If an excessive draw is verified the circuit has to be isolated, this is done by removing fuses until the draw goes away, a wiring diagram is an absolute necessity to diagnose this to identify which circuit is causing the problem. If there are any aftermarket devices installed disable them, anything like an alarm system or aftermarket stereo equipment or amplifiers etc.