I could not recall ever replacing the battery in my 2000 Saturn, so therefore I must assume that battery was more than 10 years old when it started to die. As the battery was dying, weird things began to occur; the power windows fuse blew out, the speedometer stopped working, the check engine light came on, et cetera. I got a new battery and replaced all the fuses I could locate myself, but the speedometer still refused to work and the check engine light was still on.
Apparently it is legal to drive a car with a frozen odometer if it is at least 10 years old, so I didn’t bother dealing with it. But when I got my brakes replaced, the mechanic told me that if I am correct about the cause of the check engine light, then maybe the computer was just being too sensitive and freaked out when the old battery was dying. So he decided to just reset the computer to see if the light would come back on.
Not only did the check engine light stay off, but mysteriously my speedometer was working, too. I had no idea that a frozen speedometer could be fixed by restarting the car’s computer. I guess the computer got totally whacked out by that old battery. Now The General is as good as new.