This weekend while I was out toolin' around I noticed that my volt gauge was only readind 8-10 volts. So I turned off the heater and radio and after a minute or two it had slowly made its way back up to around 13 volts. I noticed that my heater and turn signals take a heavy draw, is this normal? So what do you guys think is my alternator going bad maybe? Is there anyway to check for sure? Thanks.