I noticed when I pulled into my driveway that my Voltage meter was sitting really low... almost at 8 volts (whatever the unit is). My headlights were really dim, my wipers were running slow, and the heat wasnt as powerful. Normally I have seen my volt meter go down a little from the A/C clutch engaging and what not, from having the heater on, but goes back to normal after a couple seconds. This went on for a couple minutes before I turned everything off (wipers, heater, headlights) before it climbed back to normal. Revving it didnt help (thought maybe the RPMs were low and the altenator wasnt getting enough charge). It climbed back up on its own. Sound like a bad altenator or battery? Definetly didnt seem like a normal thing. Thanks.