Driving Lights Dim When Brake Pedal Pressed

[jzinckgra]

I notice at night when I put my foot on the brake, the headlights dim. Is this normal?

[pwall]

Definitely not!

[JB Z71]

I havn't seen that.

 

But I have noticed that my dash lights dim when I engage my power windows. I was disapointed to notice that on a 2011 as I havn't seen it on my previous trucks and it doesn't inspire any kind of 'heavy duty' image of the electrical system.

 

I'm guessing with mine it has to do on the variable output alternator. If it is in the low setting, there isn't enough juice so they dim. I wonder if that is your problem. DO they dim alot or just a little? I might have to look at mine real carefully and see if they change at all. I put it all down to the quest (for a higher mpg)

[armyman22]

I havn't seen that.

 

But I have noticed that my dash lights dim when I engage my power windows. I was disapointed to notice that on a 2011 as I havn't seen it on my previous trucks and it doesn't inspire any kind of 'heavy duty' image of the electrical system.

 

I'm guessing with mine it has to do on the variable output alternator. If it is in the low setting, there isn't enough juice so they dim. I wonder if that is your problem. DO they dim alot or just a little? I might have to look at mine real carefully and see if they change at all. I put it all down to the quest (for a higher mpg)

 

Same with mine as well as my headlights. Did it on my 02 silverado as well.

[dirtfan21]

Yes, mine do this very slightly.

[jdubub]

Mine do it too. They dim as soon as I hit the brakes but go right back to normal..... kind of like a light flicker.

[RyanbabZ71]

hmmm this topic was started earlier

 

http://www.gm-trucks.com/forums/index.php?showtopic=125426

[gnet158]

Same here on both counts, on my 08 and 02 Sierra's.

[[email protected]]

me too!!!

[jzinckgra]

So is this worth a trip to the dealer? They don't dim that much, but it is noticeable. with respect to the other thread above, my lights don't flicker, just a dimming effect.

[pwall]

I've never noticed this on my '07, not on my '02 YukonXL when I had it.

[Hieneken49]

happens to mine too

[mbaee]

You can try the dealer like I did when I noticed it (thinking there was a battery problem or something with the winter temps) and they checked the battery cables and gave me a copy of a bulletin #02-06-03-008D covering passenger cars and light trucks from 1990 - 2009 calling it normal.

 

While it may be happening frequently on many different vehicles, I certainly don't consider this normal but rather a design issue. If it was normal, it should be happening from the day it left the dealership. I noticed mine for the first time about 6 weeks ago.

[gmcgirl]

Mine does it too, noticed it last summr for the first time. My Montana did it too and it was determined to be the voltage regulator. Took the truck to the dealer and they said there was no problem. I have really noticed it alot this past week and wondered too if it was the weather - it has been super cold here in southern Ontario (minus 20C) and with the heat going full I wondered if it was underpowered somehow and causing the lights to dim. It is noticable and annoying. Since I have noticed it in the summer months I'm not convinced it is due to the cold weather. I know when it happened in the summer I also had the high beams on.

[Debo511]

It is normal opperation.