Tonight I was a having a problem where the voltage would drop for a few seconds and then come back up. At one point when I was braking it got as low as 12.6. I have also had a problem with the climate control module not remembering my settings except for temp. I put in a new battery last year but key on engine off it has never gotten above 12 volts. A few days ago I checked codes and had a lot that were power related, I checked now and there was nothing. With all of that in mind I was thinking battery but I didn't think that would cause sudden drops when driving so now I'm thinking alternator. what do you guys think? The car has never had a problem starting but last Tuesday it did seem a little slow but that's all I've ever noticed it.