mine does it when i'm driving,the G.M. guy says this is normal,alternator kickin on and off,i did some research,and found this is common,and normal,does seem weird though.i noticed it a year and a half ago,still on the same battery and alternator.
just my experience..:buhbye:
Normal....No Does it happen.... Yes It kind of depends on the status of the other system on the car. If you are cruising at a reasonable speed like 60-70 the engine isn't turning many revs, if you are running a few of the accessories the alternator is kicke din and you probably wouldn't notice any dimming if you are running everything the power windows put a draw on the electrical system the takes a few seconds to recover from. If you drop down a few gears the revs on the engine will come up and the alternator will spin faster and produce energy faster. It won't produce more since that is limited by the internals of the alternator. If your lights go out completely however, your have a very SERIOUS electrical probem that you probably don't want to think about
i think some cars even get a code and chime for "charging fault,"but it's sorta like Greg said,if all the stuff is running,and certain other conditions are meet,you may get the "alarm".hasn't happend to me though.i think this was corrected in the later 2000 models,not positive though.i don't worry about it anymore,just don't want the car in front of me to think i'm flashing my beams at them..:laughing: