, but ialways was under the impression it had to do with the alternator 
Dimming headlights
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 3,326
Likes: 0
From: Taylor TX
NCM Sinkhole Donor
Dimming headlights
My headlights have dimmed since the car was new. They only seem to dim when I hit the brakes, but they dim every time I touch the pedal. I have all stock lighting and stock stereo. How about you?
Melting Slicks
Joined: Jul 2000
Posts: 2,483
Likes: 1
From: Wilmington DE
Re: Dimming headlights (lotzahp)
lotzahp:
I had this problem and fixed it by installing direct battery power to the lights through relays and a yellow top battery. :yesnod:
If this doesn't work you could always: avoid using the headlights or never applying the brakes :D :D :D
Happy Holidays :)
I had this problem and fixed it by installing direct battery power to the lights through relays and a yellow top battery. :yesnod:
If this doesn't work you could always: avoid using the headlights or never applying the brakes :D :D :D
Happy Holidays :)
Team Owner
Joined: Jun 2001
Posts: 100,672
Likes: 2
From: Cleveland OH
Re: Dimming headlights (lotzahp)
My headlights have dimmed since the car was new. They only seem to dim when I hit the brakes, but they dim every time I touch the pedal. I have all stock lighting and stock stereo. How about you?
I have this problem sometimes... but after I had got a new battery on my old 1999C5 , it was gone.. I got and Optima Red...
Check the connections, and the battery connections...
I am not sure about the relays and battery connection but on my 2002 I have the T84 export lights and they do not dim.... but I have used a capacitor on my stereo...to protect against this...
Team Owner
Joined: May 2001
Posts: 87,409
Likes: 1,595
From: Western NY
Re: Dimming headlights (lotzahp)
I leave my house for work at 5:20 AM, so except in the middle of summer, it's dark outside and my headlights are on. EVERY day, the lights momentarily dim for a second or two, after I drive about 1/2 to 3/4 of a mile. After that, they stay steady.
Advanced
Joined: May 2001
Posts: 75
Likes: 0
From: Milpitas, Ca. USA
Re: Dimming headlights (Loadtoad)
I have an 01 6-speed, just around 6K miles, and I too have noticed this. Mine only goes dim once in a while. I've tried to find a pattern but it doesn't seem to have one. The dimming happens intermittenly. Wondering if I should take her to the dealer...
Instructor
Joined: Oct 2001
Posts: 172
Likes: 0
From: Indiana
Re: Dimming headlights (Loadtoad)
The alternator design thing is bs...They've been producing alternators forever. My Olds minivvan doesn't do this, nor any other car I've owned.
Something's up - mine dim at the first tap of the brakes and sometimes without apparent reason.
Interestingly, the DIC voltmeter doesn't drop (at least when I tap the brakes). Sound like a questionable ground somewhere to me....
Something's up - mine dim at the first tap of the brakes and sometimes without apparent reason.
Interestingly, the DIC voltmeter doesn't drop (at least when I tap the brakes). Sound like a questionable ground somewhere to me....
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Joined: Oct 2001
Posts: 1,675
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From: Central Ohio
CI 5-6-7 & 9 Veteran
St. Jude Donor '05-'06-'07-'08
Re: Dimming headlights (lotzahp)
I've noticed dimming also on my 01. It seems to happen shortly after I start
off, then I don't notice it anymore. Have thought of mentioning to dealer, but
have not as yet. :seeya :cheers:
off, then I don't notice it anymore. Have thought of mentioning to dealer, but
have not as yet. :seeya :cheers:
Melting Slicks
Joined: Apr 2000
Posts: 2,767
Likes: 4
From: Austin TX
Re: Dimming headlights (lotzahp)
I used to have the same problem (head lights dim on brake) and could really
get them to dim when I used the window against the stop.
After replacing the 2001 engine with a 2002 engine and a brand new Delco
AGM battery, the dimming problem is almost history. I have not noticed it
since the the repairs.
My guess is the the dimming was due to a weak sister battery. I would like to
know if others notice an improvement with a fresh battery. Changing the
engine is a little extreme and expensive. HiHi
[Modified by Dick Kriss, 8:17 AM 12/20/2001]
get them to dim when I used the window against the stop.
After replacing the 2001 engine with a 2002 engine and a brand new Delco
AGM battery, the dimming problem is almost history. I have not noticed it
since the the repairs.
My guess is the the dimming was due to a weak sister battery. I would like to
know if others notice an improvement with a fresh battery. Changing the
engine is a little extreme and expensive. HiHi
[Modified by Dick Kriss, 8:17 AM 12/20/2001]
Melting Slicks
Joined: Sep 2000
Posts: 2,756
Likes: 5
From: Satellite Beach, FL, USA
Re: Dimming headlights (lotzahp)
The problem is due to a NUMBER of things not just one. The C5 wiring harness is very wimpy and the voltage drops across wires can be excessive especially with loose terminals. ALL the current feeding the US headlights goes through the tiny stalk switch and the wimpy wiring going to it. There is no relay. This actually extends the life of the bulbs because there is a built in ballast "resistor", the skinny wires, keeping the bulb surge current low.
I believe that the headlight power comes from a common "tie" point that is shared by other circuits. The wire from the battery feeding this common point has to handle ALL the current needed for everything attached to the point. If other circuits connected the the point draw power, then ALL circuits will see a similar voltage drop.
At idle, the stock GM alternator has problems supplying the HUGE amount of current the LS1 engine, accessories, battery charging and lights need. This is normal, but a PITA. The LS1 engine draws more power than many other GM engines except other LS1 derivatives in trucks and maybe the Northstar which has a water cooled alternator.
I believe that the headlight power comes from a common "tie" point that is shared by other circuits. The wire from the battery feeding this common point has to handle ALL the current needed for everything attached to the point. If other circuits connected the the point draw power, then ALL circuits will see a similar voltage drop.
At idle, the stock GM alternator has problems supplying the HUGE amount of current the LS1 engine, accessories, battery charging and lights need. This is normal, but a PITA. The LS1 engine draws more power than many other GM engines except other LS1 derivatives in trucks and maybe the Northstar which has a water cooled alternator.
