Battery light stays on and voltage meter registers low on the negative side. After driving several minutes the light goes off and the meter registers straight up and down. Battery is only 3 months old. Some days the light does not come on and the meter reads fine; today however it stayed on and registered low for my 5 mile drive. Could my altenator be going out?

Yes, it sounds like the alternator is bad. If the regulated battery voltage is less than 14 to 15 volts, the voltage regulator is likely shot. Replace the voltage regulator and brushes or install a new alternator.

Thanks for your help. You confirmed what was suspected.