Lights Dim/Flicker When Rolling Windows + Sunroof

Hey Guys,

Anyone have any idea what would cause my car's lights to dim and
flicker for a split second while rolling my power windows and sunroof
? The interior lights on the guages and the outside headlights flicker
for just a second but it's noticable. I couldn't get it to do it while
the car is moving, it only happened when the car was in park or not
moving. The car is a 98 Acura Integra LS w/AUTOMATIC tranny with 75K
miles. The battery was replaced last year with a new one from Walmart.

Could this be warning sign of an alternator about to give or something
more serious ? I hope everyone can provide some help and insight on
this. The car does start fine and runs well. Thanks for any help this
group can provide.

 

Try doing the same while stepping on the brakes. The ECU signals the
alternator to lower the voltage when you are idling with a warmed-up
engine (plus another few requirement). Stepping on the brakes puts the
voltage back to normal.

Both the sunroof and power windows draw a lot of current, particularly
at start-up, so some dimming of lights when the alternator is in
power-save mode is not unexpected.

 

Remember those windows are heavy. Especially when you have to lift them
vertically (door windows) compared to moving them horizontally (sunroof).
The motor for the power window has to be strong and requires a lot of
current to do the work that is required. As Randolph explained, the power
output of the electrical system is lowered when you're idling, thus using
the power windows while idling is noticable as you've observed (dimmed
headlights, dash lights, etc.) While you are moving it's not as noticable
but your headlights are still dimming. Turn your radio on and try moving the
power window and you'll notice your headlights dimming in the evening.

That's nothing to worry about. If you want less dimming, you can get a more
powerful alternator which will increase the power output of the electrical
system thus when the power windows are used, especially with other
electronics turned on, it will be less noticable, if at all (depends on
alternator you choose).

I have a 98 accord ex with stock alternator and it does the same thing.
Again, money solves problems... or does it?

--Viktor