seems like the headlights are running off the battery. when I start the car which is a 85 Camaro the amp gauge reads around 12.5 when the lights are turned on the starts to fall. and if I drive it to work about 7 miles from home with the lights on the gauge will read aroumd10 and will not start the car. I got a new battery and replaced the alternator.is there a relay that could be bad?