My 94 Z28 has been staying in the red zone for months of driving. I check it with Freescan and it is always around 11.7-12.2 volts. I have replaced the battery, the alternator is about a year old but is their anything else like wiring or voltage regulators that could be causing this scenario. Again it keeps it charged and when you crank it you can see the guage go up while it is recharging more than while cruising but generally it will stay in the voltage range above. It has been this way for along time I figure it is the alternator but want to get another opinion since I am no expert on charging systems.