headlights only go down with brights on
Thread Starter
Instructor
Joined: Mar 2004
Posts: 101
Likes: 0
From: Chapel Hill NC
headlights only go down with brights on
i drove my car this morning and when i stopped i realized that the headlights didn't go down when i the switch built into the left stalk. i got out and looked and the lights were off regardless of the switch being up or down. The odd thing was the brights still worked while the switch was set to on, and the flashing of the brights stil lworked with the headlights set to off.
I got back to the car and played with the lights after class and figured out that the lights would retract only when i had the bright lights on.
anyone have any ideas whats going on?
I got back to the car and played with the lights after class and figured out that the lights would retract only when i had the bright lights on.
anyone have any ideas whats going on?
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
I'll take a wild guess that the headlamp controller has a problem, but first look at splice pack 100 on the right forward frame rail, just in case. It could also be the headlamp switch itself.
Team Owner
Joined: Sep 2002
Posts: 30,570
Likes: 4,609
From: Bonita Springs, Florida
Sounds like a bad headlamp switch in which case you will need to pull the steering wheel and replace the stalk with the headlight controls. Call Gene's Kar Shop, he should have used ones for a fraction of the price of a new stalk.
Thread Starter
Instructor
Joined: Mar 2004
Posts: 101
Likes: 0
From: Chapel Hill NC
I dont actually know what the 100 pack is. Anyone care to explain. Also more details. I had more time to play with the headlights today. The twilight setting allows them to go up when the switch is set to off but the lights never come on in low beam, but they come on using twilight in high beam. Even weirded the lights don't go down when i leave the car in twilight. Basically if you turn the lights on in either the low or high beam setting, the lights pop up and only work if the brights are engaged (stalk pushed forward) if you turn the rotary end of the stalk to turn off the lights and the lights were set to low beam, the pop ups stay up (the car even beeps at you when you leave because it thinks the lights are on. As soon as you flick the stalk to high beam with the rotary to off, the lights go down
all very weird....
all very weird....
Le Mans Master
Joined: May 2007
Posts: 5,383
Likes: 6
From: hagerstown md
St. Jude Donor '08-'09
I would bet it's the low beam fuse. He states the lights are OFF regardless if he has them turned on or off, and the highs come on, go back down, and flash fine. So, he isn't getting power to the low beams. Blown fuse most likely. 
Last edited by sneakelman; Nov 27, 2007 at 09:08 AM.
Pro
Joined: Jun 2001
Posts: 674
Likes: 2
From: Angleton Tx
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Splice pack 100 is mounted on the right forward top of the frame rail at slightly rear of the actual hood hinge mounts. I just had to remove mine totally and solder the wires together into terminal lugs due to loss of ground connections at the wire crimps to pins themselves. A lot of the lighting grounds go through that splice pack. Bill Curlee has a some great pictures of it if you PM to him. He's the resident expert here on electrical and might be able to better advise you.
4th Gear
Joined: May 2025
Posts: 4
Likes: 0
Having same issue
I dont actually know what the 100 pack is. Anyone care to explain. Also more details. I had more time to play with the headlights today. The twilight setting allows them to go up when the switch is set to off but the lights never come on in low beam, but they come on using twilight in high beam. Even weirded the lights don't go down when i leave the car in twilight. Basically if you turn the lights on in either the low or high beam setting, the lights pop up and only work if the brights are engaged (stalk pushed forward) if you turn the rotary end of the stalk to turn off the lights and the lights were set to low beam, the pop ups stay up (the car even beeps at you when you leave because it thinks the lights are on. As soon as you flick the stalk to high beam with the rotary to off, the lights go down
all very weird....
all very weird....
Drifting
Joined: Nov 2017
Posts: 1,392
Likes: 303
My car has done this intermittently since I switched to LED headlights.
I assume there's something that looks for a drop in power consumption to trigger the popup retraction, and since power draw isn't as high as it was, the drop isn't as big as it was, so it goes unnoticed.
I assume there's something that looks for a drop in power consumption to trigger the popup retraction, and since power draw isn't as high as it was, the drop isn't as big as it was, so it goes unnoticed.
4th Gear
Joined: May 2025
Posts: 4
Likes: 0
It's not really the having to use the bright to make the headlights go down that is bothering me it's that my low beams don't work. I am only getting 5.5v to the low beam. I work midnights so I am always driving at night. I know the headlights are angled lower than most cars so it's not terrible for the others driving at night but I still feel like a jerk
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
Likes: 4,055
From: Cape Coral, Florida
It's not really the having to use the bright to make the headlights go down that is bothering me it's that my low beams don't work. I am only getting 5.5v to the low beam. I work midnights so I am always driving at night. I know the headlights are angled lower than most cars so it's not terrible for the others driving at night but I still feel like a jerk
If you have 5.5 volts you may have high resistance or a bad ground…how did you check the circuit ??
Last edited by C5 Diag; May 16, 2025 at 05:42 PM.
4th Gear
Joined: May 2025
Posts: 4
Likes: 0
I have already taken off every ground on the car and wire brushed them, I ohm tested every connection from the fuse box to the headlights and have continuity, I have not voltage tested every connection yet since I ran out of time yesterday but I am going to today
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
Likes: 4,055
From: Cape Coral, Florida
No my friend ohm (resistance) testing a circuit is NOT the correct way to test and if someone tells you it is they know nothing about electrical testing…if you had 100 strands of copper wire and ohm tested it and then removed 1/2 of them the resistance will still be the same…that wire will not be able to carry that same amount of current and that is what’s important…if you have resistance on the ground side the load (the headlight) will not be able to use that current…loaded circuit testing using voltage drop is how it’s done…and remember that if there is no current flow there is no voltage drop…the circuit had to be “loaded”…watch the video and there are many more YouTube videos on this subject.
4th Gear
Joined: May 2025
Posts: 4
Likes: 0
Its fixed!!
Okay so having to put the headlights in bright mode to make them go down was the DRL/ headlight control module being bad, I got a new one for 100$. The low beam not working was in fact a bad ground, I did the the voltage drop test and I was losing voltage at the driver side ground connection, I ended up having to splice in a new part of wire where the ground wire was fraying. I can't believe ohm testing is basically useless lmao... All the maintenance guys at work were telling me to ohm test too 🤣. Thank you so much for your help your the goat. I'm only 20 and this is my first project car so I still have a lot to learn.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
Likes: 4,055
From: Cape Coral, Florida
Okay so having to put the headlights in bright mode to make them go down was the DRL/ headlight control module being bad, I got a new one for 100$. The low beam not working was in fact a bad ground, I did the the voltage drop test and I was losing voltage at the driver side ground connection, I ended up having to splice in a new part of wire where the ground wire was fraying. I can't believe ohm testing is basically useless lmao... All the maintenance guys at work were telling me to ohm test too 🤣. Thank you so much for your help your the goat. I'm only 20 and this is my first project car so I still have a lot to learn.
Great news !!…now you can teach those maintenance guys at work who are clueless…keep up your electrical training and you will be miles ahead than 99.9% of most mechanics…subscribe to the YouTube channel below if you really want to know how to diagnose cars !!
