driving home my check battery light comes on when i turn on the a/c fan. Turn the fan off it goes off. then all of a sudden my guages start jumping around and bottoming out for about a minute then act normal. about 5 minutes later they start jumping around again and the check battery comes on. I finish driving it home and park it. about 2 weeks later i am going out to start checking to see if i can find anything wrong with it and the battery is totally dead. It's down to 1.5 volts. Can this be that the voltage regulator went bad. I had another vehicle that was parked beside it and the mice got under the hood. I couldn't find any sign of that on this car. Can anybody give me a place to start checking what might be wrong?

 

Have the battery checked out to see if it is good or bad
Then with battery (good one) installed, read the voltage with multi-meter
Start engine and read voltage while engine is running
Turn lights and AC on and then read the voltage

The voltage with engine off should be around 12.5 volts
The voltage with engine running should be around 13.5 to 14.5 volts

After engine is started, the alternator takes over providing the electricity the vehicle needs to run.
If your battery voltage is low it may not hold a charge.
When the alternator is not putting out enough voltage, it may drain the battery and not provide the need power to run the vehicle.

If your electrical system doesn't have enough power then all sorts of crazy things could happen.