Headlight problems
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
Headlight problems
Hey guys,
on my 1979 Corvette, my headlights don’t even turn on anymore when I pull the switch my side marker dash lights fog lights everything will turn on but the headlights will not even turn on or pop up. I was in there recently, putting in a new fog light bulb, but I don’t remember unplugging anything that would affect those main headlights. If anyone has any ideas on what it could be and what I should look for to diagnose this issue, it would be greatly appreciated
thank y’all,
air_drewdy
on my 1979 Corvette, my headlights don’t even turn on anymore when I pull the switch my side marker dash lights fog lights everything will turn on but the headlights will not even turn on or pop up. I was in there recently, putting in a new fog light bulb, but I don’t remember unplugging anything that would affect those main headlights. If anyone has any ideas on what it could be and what I should look for to diagnose this issue, it would be greatly appreciated
thank y’all,
air_drewdy
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,780
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
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Cruise-In VIII Veteran
Won't turn on is electrical. Won't pop up is vacuum.
unless they have been converted.
Sounds like I would start at the switch. Are you getting power to the switch? Tail lights work, so most likely. Are you getting power out of the switch? (On its way to the high/low switch?
As per pop up. Check vacuum lines at the switch. pull the override switch under the column. Do they come up?
unless they have been converted.
Sounds like I would start at the switch. Are you getting power to the switch? Tail lights work, so most likely. Are you getting power out of the switch? (On its way to the high/low switch?
As per pop up. Check vacuum lines at the switch. pull the override switch under the column. Do they come up?
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
Won't turn on is electrical. Won't pop up is vacuum.
unless they have been converted.
Sounds like I would start at the switch. Are you getting power to the switch? Tail lights work, so most likely. Are you getting power out of the switch? (On its way to the high/low switch?
As per pop up. Check vacuum lines at the switch. pull the override switch under the column. Do they come up?
unless they have been converted.
Sounds like I would start at the switch. Are you getting power to the switch? Tail lights work, so most likely. Are you getting power out of the switch? (On its way to the high/low switch?
As per pop up. Check vacuum lines at the switch. pull the override switch under the column. Do they come up?
yes, it does seem I’m getting power to the switch my tail light side marker fog lights stash lights. Everything turns on but the headlights themselves don’t which is very odd to me. They used to pop up when I would pull the switch and vacuum wise has changed so I don’t think I have a massive vacuum leak causing that to happen. I will pull override to see what do you think I should check next
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,780
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Yes of course. That's why I asked him to check power out of the switch to the high/low switch. Gotta start somewhere.
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
i made sure the switch works it dims the lights on the interior. Every single light on this car works but the headlights and the vacuum still works. The filaments look okay.
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
Okay quick update here. Before I retired the car for the night after trying to figure this out I played with the switch a bit. And I noticed it clicks into place for the first click that turns on all of the lights but the headlight. But when I try to pull it out further for the headlight it doesn’t seem to click. Do these switches have to clicks for the headlights? Could it be my switch can’t make the connection to turn on the headlights? If so how do I test it?
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Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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Cruise-In VIII Veteran
Yes, first click is tail lights, running lights, dash lights. Second click is headlights. Sounds like something is preventing you from moving it to the headlights position. Didn't I mention to get to that switch and check it? Yes you need to pull the dash. No, there isn't a shortcut.
Melting Slicks
Joined: Sep 2004
Posts: 3,223
Likes: 666
From: Northeast
This will give you an idea of what the switch looks like & how to remove it. . He does make it seem simple for a 79 but I would be concerned about any damage to the dash by pulling it out.
Might not be your problem but a good link to save.
Might not be your problem but a good link to save.
Team Owner
Joined: Jun 2001
Posts: 23,367
Likes: 1,061
From: Virginia USA
If the '79 circuit is anything like my '71 circuit ALL the headlight current is going through that switch. There are stories about them catching fire. There are stories of the Chinese aftermarket switches being defective right out of the box (I have one). If the circuit is the same I suggest installing relays to upgrade the circuit and upgrading the load carrying wires from the relays to the lights to a larger gauge. This eliminates the high current through the switch in the dash and the high current is now though the relays instead. Search for the threads, there are many.
Just a suggestion.
Just a suggestion.
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
Yes, first click is tail lights, running lights, dash lights. Second click is headlights. Sounds like something is preventing you from moving it to the headlights position. Didn't I mention to get to that switch and check it? Yes you need to pull the dash. No, there isn't a shortcut.
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
This will give you an idea of what the switch looks like & how to remove it. . He does make it seem simple for a 79 but I would be concerned about any damage to the dash by pulling it out.
Might not be your problem but a good link to save.
https://www.youtube.com/watch?v=RrUO-aczSD4
Might not be your problem but a good link to save.
https://www.youtube.com/watch?v=RrUO-aczSD4
Thread Starter
Instructor
Joined: Dec 2023
Posts: 166
Likes: 14
From: Chicago IL
If the '79 circuit is anything like my '71 circuit ALL the headlight current is going through that switch. There are stories about them catching fire. There are stories of the Chinese aftermarket switches being defective right out of the box (I have one). If the circuit is the same I suggest installing relays to upgrade the circuit and upgrading the load carrying wires from the relays to the lights to a larger gauge. This eliminates the high current through the switch in the dash and the high current is now though the relays instead. Search for the threads, there are many.
Just a suggestion.
Just a suggestion.