Why does my battery keep going dead?

Make sure your rear brake lamps are turning off after you park the car. If not replace brake light switch behind brake pedal. Corolla models had trouble with this.

Check your wiring at the connector to the alternator. On my 97 Corolla, I noticed that the lights were dimming as I returned home one night. When I connected my meter to check the alternator voltage it was at 11.8 volts DC. I reached down and wiggled the wiring that goes into the connector which plugs into the alternator and as I did it the meter began showing 14.23 volts DC. The next morning, I carefully removed the wiring from the connector and after a bit of soldering and installation of shrink tubing, the problem was resolved.