This hasn't really been a problem yet, but I just wanted to make sure.

Anyway, I've noticed lately that my voltage gauge occasionally dips from the usual 13V to right around the red area. I can feel the AC lose some power and the lights dim (if they're on), but then it comes right back after a second or two. From what I can tell, this usually only happens when it's really hot out (middle of the afternoon, especially if the car's just been sitting in the sun for a few hours), and oddly, when I brake/turn corners.

Is this anything to worry about?

 

Your power steering pump may be failing and putting a bigger load on the system causing the RPMs to drop, thus causing your voltage and AC to drop.

 

Interesting, how would I test this?

 

When was the last time you changed your belt? Might want to check the tensioner too.

 

Also get a load test done on the battery...

 

Could be a sign that your alternator about to go in the dump.

 

Mine will do the same thing in the hottest part of the day when I have the A/C on high max and I kick my cooling fans on high speed. The load from the A/C clutch plus the blower motor on high along with two cooling fan motors starting up on high speed really loads the charging system and it takes a second or so to catch up. At least thats my theory and I'm not going to worry about it. My battery might not be holding a load quite as good as it should and that might be playing a part in why it does it but it starts fine and charges fine so I'm not too concerned.