Dimmed headlights
Thread Starter
Le Mans Master
Joined: Mar 2007
Posts: 6,007
Likes: 2
From: Manteo NC
Dimmed headlights
Driving home last night my wife pushed the button to put her window up, when it reached the top the headlamps and dashlights dimmed for a second or two. Has anyone else had this problem and is it something to be worried about?
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Is your battery the original? If so I'd start by changing that as a pre-emptive measure. The old AC Delcos are prone to leaking and it could be on its way out. If the battery is causing power spikes you should get a few lost comm codes on the DIC.
If its a newer battery, check the connector in the rubber gaiter in the door hinge area. Its been known to come loose and cause weird electrical gltches. In any event check the battery leads are tight and there are no leaks.
If those fail it may be a module issue.
If its a newer battery, check the connector in the rubber gaiter in the door hinge area. Its been known to come loose and cause weird electrical gltches. In any event check the battery leads are tight and there are no leaks.
If those fail it may be a module issue.
Thread Starter
Le Mans Master
Joined: Mar 2007
Posts: 6,007
Likes: 2
From: Manteo NC
Is your battery the original? If so I'd start by changing that as a pre-emptive measure. The old AC Delcos are prone to leaking and it could be on its way out.
If its a newer battery, check the connector in the rubber gaiter in the door hinge area. Its been known to come loose and cause weird electrical gltches. In any event check the battery leads are tight and there are no leaks.
If those fail it may be a module issue.
If its a newer battery, check the connector in the rubber gaiter in the door hinge area. Its been known to come loose and cause weird electrical gltches. In any event check the battery leads are tight and there are no leaks.
If those fail it may be a module issue.
Advanced
Joined: Aug 2006
Posts: 81
Likes: 0
From: Dearborn Heights MI
More than likely becasue when the window reaches the top the motor needs to draw more current to try and move it, but it won't move. Seen this on a lot of cars, and I rent a lot of cars through work (I travel a lot).
Instructor
Joined: Jan 2004
Posts: 175
Likes: 0
From: Loughborough, UK
Replaced the original battery with an optima yellow top (about a year ago), I've had no such issues since.
The batteries on these cars need to be 100% or you start to see such electrical gremlins, just think yourself lucky that you don't have a C4!.
Good Luck.
Burning Brakes
Joined: Jan 2006
Posts: 967
Likes: 344
From: Yazoo City Mississippi
on my car and truck if you hit both window buttons at once you can see the volt meter drop a little
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Joined: Jan 2007
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From: Manteca, CA
If you look at the general amperage usage of window motors, they tend to be at the high end of the scale of vehicular accessories in power usage.
Your charging system is rated at a certain amperage level, and when using a lot of electrical accessories (radio, defroster, AC, lighting, windows, etc) it can actually tax the system enough to see the draw in the headlights dimming. It is totally normal, since you are using the power to do everything, including keeping the car running.
You may even see your lights dim while slowing down to an idle speed, due to the change in the rpm at the alternator.
Your charging system is rated at a certain amperage level, and when using a lot of electrical accessories (radio, defroster, AC, lighting, windows, etc) it can actually tax the system enough to see the draw in the headlights dimming. It is totally normal, since you are using the power to do everything, including keeping the car running.
You may even see your lights dim while slowing down to an idle speed, due to the change in the rpm at the alternator.
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Joined: Jun 2005
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From: Lenoir City TN
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