My 1994 LS gives me irregular readings from the voltage meter. It shows around 13 volts sometimes, and under 12 at other times. I have checked the output at the alternator,and battery, and it is reading 13.8 volts. Just recently I used a different key, and it was consistantly showing 13 volts, but at times when I started it the CD player would not come on, or could not be turned on. If I stopped it, removed the key and then started it everything would work. I tried the other key today, and everything always worked when I started it, but the voltage was at times showing below 12 volts, and other time 13 volts. I am thinking the ignition, any suggestions.