Headlight and Dashlight Flicker

2001 Olds Intrigue 3.5
Over the last couple of months I have noticed that mainly on the highway my headlights and dashlights will flicker and dim. It does it very speratic. Performance does not seem to be affected and it will still do it with the heater radio etc... (all other electronic devices off). I drive from Arizona to Colorado alot, this last time lights were fine from AZ all the way to the CO border then acted up for about 10 minutes or so then were fine until I got to the hotel.

Is this the infamous alternator issue I have read about or something else??

Thank You to all who reply!

It sounds like the alt. problem but I thought GM fixed that by 2001 - maybe not. Is the weather colder than normal when this happens? Mine doesn't act up til the weather turns cold.
Other than being annoying it doesn't seem to hurt anything - my '99' has 102,000 miles w/ the orig. alt and has done this since I had it (15,000 miles).

I only first noticed it about two months ago...when it started to get cold...very highly possible. Thanks

My 2001 did the same thing . It turned out to be the air injection pump, which is mounted on the lower left frame in front of the drivers side wheel. This pump as it starts to go bad draws big amps. which will cause the lights to filcker. as time goes on the pump will seize up and blow the 50 amp fuse and set a check engine light and a error code of P410. I hope this helps.