I forgot to ask you, how long has has it been doing this? Does your lights go dim at night? The reason I ask is because if it is your alternator, that's a sign that it's going bad. You might want to check it with a volt meter to see how much voltage it's pushing. Just put the + lead of the volt meter to the connector on the alternator, then put the - lead to ground. If I'm not mistaken, I think it should read somewhere betwwen 13.5-14.1 volts. If it reads lower than that, there is a problem with your alternator. Or you could simply take it to AutoZone or Advance and have them check it out. That will tell you if the bearings are going bad in the alternator. If they are going bad, your voltage at the alternator will read lower than it normally would. Hope you get it fixed.