what is the voltage meter supposed to be at because mine reads almost 3/4 of the way to 18?
my battery went dead but its kinda of new 6 months old.
I think it might be my alternator?
How would I know if my alternator is working correctly?

 

If you put a voltmeter on the battery posts when it is running, you should have 14 to 14.5 volts. It should also be above 13.5 if you turn on headlights, wipers, heater fan, rear defroster, etc.

Also make sure the alt belt is tight enough, and is not glazed. If it is slipping, it acts just like bad alternator.