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Dimming headlights....
Thread Starter
Racer
Joined: May 2006
Posts: 437
Likes: 0
From: Itasca IL
St. Jude Donor '12
Dimming headlights....
Anyone experiancing dimming headlights while driving? I get a flicker once in a while and can't figure out why? New battery was installed last summer. Please chime in....
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
I've seen this same thing in my '99 for the entiire life of the car. I believe it happens when the alternator switches from high rate charge to a lower rate charge or when the rpm falls off enough during the high rate charge mode. Having said all that, I think its the built in regulator, but there has never been a problem on mine with that system.
Race Director
Joined: Jan 2004
Posts: 10,231
Likes: 344
The only times I've had this problem are when I push the power window buttons (drain on system; perfectly normal from what I hear) or when my serpentine belt went out. I assume this isn't happening to you. 
Former Vendor
Joined: Nov 2005
Posts: 8,995
Likes: 2
From: Spring Texas
St. Jude Donor '08
the "big 3" mod can help solve this problem:
It involves running three 4 awg wires:
a) from alternator mounting bolt to frame
b) from alternator positive to battery positive
c) from battery negative to frame
Your stock alternator (depending on it's model) has a output capacity of 110 or 140 amps. Your stock charging cable is thick stranded 8 awg and has a carrying capacity of less than 100 amps.
Running the 4 awg wire IN ADDITION to the stock wires reduces the resistance on your alternator significantly allowing it to work more effectively.
here's my setup:
without alternator:
wires through battery compartment wall:
Grounding points on the frame are up to the user. The hood frame mounts are wat i'm currently using. i reccomend purchasing special grounding feet for the wires for maximum current transfer.
See the audio section for more information.
It involves running three 4 awg wires:
a) from alternator mounting bolt to frame
b) from alternator positive to battery positive
c) from battery negative to frame
Your stock alternator (depending on it's model) has a output capacity of 110 or 140 amps. Your stock charging cable is thick stranded 8 awg and has a carrying capacity of less than 100 amps.
Running the 4 awg wire IN ADDITION to the stock wires reduces the resistance on your alternator significantly allowing it to work more effectively.
here's my setup:
without alternator:
wires through battery compartment wall:
Grounding points on the frame are up to the user. The hood frame mounts are wat i'm currently using. i reccomend purchasing special grounding feet for the wires for maximum current transfer.
See the audio section for more information.
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
Check your battery terminals, make sure they are tight. If you can move them by hand, they are too loose.
Be careful, over tightening battery bolts can cause it to leak, only use 11 ft-lbs torque.
Be careful, over tightening battery bolts can cause it to leak, only use 11 ft-lbs torque.
Last edited by Oldvetter; Apr 21, 2007 at 12:09 AM.
Former Vendor
Joined: Nov 2005
Posts: 8,995
Likes: 2
From: Spring Texas
St. Jude Donor '08
Drifting
Joined: Jul 2004
Posts: 1,345
Likes: 0
From: Between Boston and Cape Cod MA
Mine has done the same thing since I have owned it . It seems to "dip " in voltage for just a split second . It goes away when the car is all warmed up .
Not yet a problem , just strange .
Not yet a problem , just strange .
Safety Car
Joined: May 2004
Posts: 4,811
Likes: 2
From: Simpsonville SC
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Thread Starter
Racer
Joined: May 2006
Posts: 437
Likes: 0
From: Itasca IL
St. Jude Donor '12
I'm glad to hear I am not the only one with this problem. It has been happening since I bought the car also(1 1/2 years ago) I will check the terminals to make sure they are tight, but not to tight. I will also look into doing "The big three". Thanks again for all your input
Race Director
Joined: Feb 2004
Posts: 11,651
Likes: 9
From: HOW FAST WAS I GOING OFFICER? Los Angeles Hating GM Dealership Service Dept.'s Since Sept. 2004
St. Jude Donor '04-'05-'06-'07
When I had OEM lights, mine did it, even on other cars. I thought it was "normal". 
The big 3 idea is awesome from what I've read. I never got around to it.
The big 3 idea is awesome from what I've read. I never got around to it.
Safety Car
Joined: Mar 2007
Posts: 3,518
Likes: 37
I also ran an extra ground to my alternator along the way to finding out I had a loose positive termainl. Question is: Isn't the alternator already grounded being massively bolted to the engine which is bolted to the frame? Or is the engine not grounded? Thanks.
Former Vendor
Joined: Nov 2005
Posts: 8,995
Likes: 2
From: Spring Texas
St. Jude Donor '08
If i rember correctly the engine is slightly grounded but the resistance through all the bolts, mounts and crap all adds up. The only reason to run 2 ground wires is because most of the electrical components use the chassis as a ground.
Racer
Joined: Nov 2006
Posts: 491
Likes: 5
From: Tampa Bay Area, U.S.A. (Zombie Nation)
If I missed this, sorry, but could you give some details on that blue wire you used for your "Big 3" mod"? I suspect it has a copper conductor(?) but the blue insulation is what I'm especially curious about - how it holds up under engine heat and so forth.
