lights dim for short time

[uofmz71]

my lights dim sometimes when i put the brake on, but this usually only happens once or so each session of driving (on then off)

does this happen to anyone else?

im not worried about it just curious - should i get a new battery?

EDIT: im talking about the headlights...

 

[kpanza]

Mine has been doing this for a while now...except mine does it several times each trip usually, not just once. Next time I'm at the stealership, I'm gonna have them check it out. It's annoying to say the least...and like you say, it seems to usually happen as I'm braking or coming to a stop on a roll...I assume that the alternator is having a momentary deficiency in output, causing the lights (one of the bigger electrical draws) to quickly dim.

But you're saying your's only does it once per trip or so? In my typical 15 mile drive home (often in bumper to bumper traffic), I'd say it averages 5-10 times of "dimming"...I've had it do it with A/C both On and Off, so seems to be independent of that (although the A/C is On Auto more than it's off...)

My bet is on the alternator...I've had some quirky electrical systems in my past GMs, they still can't seem to get that down...hopefully it's something simple.

 

[uofmz71]

yeah maybe only once... but i really cant tell sometimes, my windshield is tinted so that kinda throws the perception a little. and sometimes it doesnt do it at all. but i thought i was crazy thinking my lights were doing this! haha

i guess ill tell the stealership as well... let me know what they say about yours...

 

[jnicks01]

I have this issue too, but mine happens frequently. More so when it's just been started again after sitting all night. I'm actually changing out my alternator this week. I will let you know if it helps.