You did not mention if you are having problems with your battery, but often if you are blowing light bulbs, your alternator is overcharging. In good condition with a good battery, alternator output should be from 12.6 volts up to as much as 14 volts. In some cases you might see 14.2-14.4 volts. Any more than this and your battery will get hot and stink, and you will blow light bulbs as fast as you can put them in.