Re: Do I nedd a new alternator?
To test the alternator, get the engine running and with a volt meter, measure the voltage at the battery terminals. The reading should be from 14 - 14.5 volts with no lights/accesories on if the alternator/voltage regulator is good and the battery is bad. If the reading is lower, it may be from a loose alternator belt or a bad voltage regulator. When the engine is running and you turn on the headlights, the battery voltage should stay at the above voltage. If not, the voltage regulator is bad. In the above test, if you get a reading below 14V (say 12-13V) it could also mean a defective alternator. If the battery is bad, when you turn off the engine after several minuets, the battery voltage will start to drop quickly and reach below 12V within several minuets to an hour with nothing turned on.
Driving it forever, or close to it