Dimming lights
Thread Starter
Racer
Joined: Jul 2006
Posts: 275
Likes: 25
From: West Lafayette IN
Dimming lights
I've noticed that when I hit my brakes or when I move my seat a little in the mornings or at night my lights dim. So I started to watch the digital gage of the battery voltage. Sure enough when I hit the brakes or when I roll the windows down or anything like that the voltage dips down. This isn't a major deal, but I'd like to know if anyone else has seen this and/or knows a fix for it?
Thanks
Shane
Thanks
Shane
Drifting
Joined: Nov 2003
Posts: 1,894
Likes: 6
From: Sahuarita AZ
Originally Posted by hihoSilver
My 2002 has always done this. Mine even slightly dims when blinker lights on. Does it worse when rolling down window.
My lights dim when rolling the windows up/down as well. I think this is common.
Instructor
Joined: Aug 2006
Posts: 182
Likes: 0
From: Hartsville SC
Originally Posted by torchredfrc
My lights dim when rolling the windows up/down as well. I think this is common.
I notice this too with a bone stock 03 coupe
Safety Car
Joined: Jun 2004
Posts: 3,717
Likes: 0
From: Palmdale CA
St. Jude Donor '06
Mine did it with the stock delco battery as well as when I replaced it with a red top. Not a real issue so I haven't really given it a second thought. It would be good to know what the cause might be. 
Drifting
Joined: Nov 2003
Posts: 1,894
Likes: 6
From: Sahuarita AZ
Originally Posted by Ephedranator
Could this be an indication of batter problem or weakness? Do any of you guys have a different battery from the stock Delco?
I notice this too with a bone stock 03 coupe
I notice this too with a bone stock 03 coupe
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Drifting
Joined: Nov 2003
Posts: 1,894
Likes: 6
From: Sahuarita AZ
Originally Posted by tripblkvert
Im guessing grounding issue
Burning Brakes
Joined: Jun 2003
Posts: 1,100
Likes: 0
From: The Great State of Texas
CI 7-8 Veteran
I had a 99 Trans Am that did it and now have a 02 Vette which does it. I was told by a GM service guy that it is normal for the lights to dim like this. Of course we all know that GM service people always speak the truth.
Melting Slicks
Joined: Oct 2001
Posts: 2,320
Likes: 2
From: Salem Oregon
My 98 does this also. I noticed on the hot battery cable, there is a thicker red wire that comes out and goes to, I think the fuse box.
There is a slight nick in that wires sheathing,a few inches from the battery, and the wire inside is corroded pretty good.
I am going to change it out this winter, and see if that helps. If it doesn't, I am not going to worry about it.
Randy
There is a slight nick in that wires sheathing,a few inches from the battery, and the wire inside is corroded pretty good.
I am going to change it out this winter, and see if that helps. If it doesn't, I am not going to worry about it.
Randy
Thread Starter
Racer
Joined: Jul 2006
Posts: 275
Likes: 25
From: West Lafayette IN
Ok good to know. I have a red top in he car already. This is my first vette, but I've had lots of GM's never had this happen. I wondered if it could be a ground problem. I thought i might have one anyway.
I tell you if I turn up the stereo and my amp kicks in a little (10" sub) its really bad. Lights turn into 4-way flasthers.
I tell you if I turn up the stereo and my amp kicks in a little (10" sub) its really bad. Lights turn into 4-way flasthers.
Pro
Joined: Jul 2006
Posts: 529
Likes: 1
From: Princeton Texas
If you are talking about it happening when the engine is off, then it happens becouse you are putting an extra load on the battery with each power item you operate. If engine is running it will do the same to the alternator. Much like the lights in a house flicker when the air cond. kicks on. This is all normal. The only thing the battery is for is to start the engine. If the alternator is working it takes over the electrical load as soon as the engine starts. In the old days if your battery was down and you didn't know if the problem was battery or alternator you could push or jump the car to get it running, then lift off the neg. battery cable. If the car kept runing it was the battery. If it died the alternator was bad. You should not do that today on cars with computers as you can fry one.
Last edited by Flat Broke; Oct 11, 2006 at 12:17 AM.
Melting Slicks
Joined: Jul 2006
Posts: 2,094
Likes: 5
From: The 7th layer of hell - Western Washington
My 97 Firebird did it, and so does my 02 Z06. It is minimal most of the time, but is very noticeable when raise both windows at night with high beams and fogs on.
Instructor
Joined: Aug 2006
Posts: 182
Likes: 0
From: Hartsville SC
I havent looked up the specs on our alternators, but I thought they were pretty beefy?
Would an upgraded alternator help this, it really bothers me when my lights dim from hitting the brakes.............just doesnt seem right
Would an upgraded alternator help this, it really bothers me when my lights dim from hitting the brakes.............just doesnt seem right
Burning Brakes
Joined: Dec 2004
Posts: 1,067
Likes: 3
From: Lost in the Pine Barrens with only ketchup and relish packs, New Jersey
Try driving with the headlights on and both windows up. Then tap both of the window up buttons (even though they are already up) at the same time, it is almost enough to put the lights out...
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
dimming lights
Any time you take current from the alternator/battery you will reduce the voltage. Seat motors take a lot of current especially if at the stops also same for windows. THIS IS NORMAL. Regulator senses voltage drop and gives alternator more field current. VOLIA voltage goes up. The greater load you have on the system ie. lights on windshield wipers on blower and a/c compressor on the more current you are using. As long as your engine is running and alternator is charging NO PROBLEM.