Headlight issue
Thread Starter
7th Gear
Joined: Jun 2025
Posts: 7
Likes: 0
Headlight issue
HELP!
This past week I had my dash out to replace my tachometer. When I put the dash back together my headlights were not operating properly. Both left and right popped up when I started the car before I turned the light switch on. Neither headlight turned onbut the dash lights illuminated. When i shut the car off the right headlight closed but the left headlight stayed up.
This seems like a switch issue to me but before i took the dash apart again I wanted to ask the experts.
Any Ideas? Thanks in advance.
By the way my car is a 1968 and the lights worked perfectly before I took the dash apart.
This past week I had my dash out to replace my tachometer. When I put the dash back together my headlights were not operating properly. Both left and right popped up when I started the car before I turned the light switch on. Neither headlight turned onbut the dash lights illuminated. When i shut the car off the right headlight closed but the left headlight stayed up.
This seems like a switch issue to me but before i took the dash apart again I wanted to ask the experts.
Any Ideas? Thanks in advance.
By the way my car is a 1968 and the lights worked perfectly before I took the dash apart.
Drifting
Joined: May 2020
Posts: 1,661
Likes: 697
From: Baton Rouge, Louisiana, metro area
I assume they were working properly before the work?
Did you mark the hoses and put them back like they were?
maybe your switch was cracked during the work you did, or you put your vacuum lines back incorrectly causing constant vacuum to the wrong side of your valves.
I would start with low hanging fruit and double check my hose routing.
Did you mark the hoses and put them back like they were?
maybe your switch was cracked during the work you did, or you put your vacuum lines back incorrectly causing constant vacuum to the wrong side of your valves.
I would start with low hanging fruit and double check my hose routing.
GM Cert Corvette Tech
Joined: Apr 2008
Posts: 2,559
Likes: 585
From: Anaheim Hills California
Check the vacuum lines going to the headlight switch. It sounds most likely that you may have pulled one of them off the headlight switch when you pulled out the gauge cluster.
Pro
Joined: Sep 2020
Posts: 740
Likes: 750
From: Chapin SC 29036
My guess is that you have a couple of vacuum lines reversed. It does make a difference. Here is a vacuum diagram. It was made for a 69, but it is basically the same as the 68. You can get to the headlight switch from the top. If you remove all the screws and lower the steering column, you can carefully pull the top left of the panel out enough to get to the switch. Don't force it as it is possible to break an old panel and replacing it is not fun and you never know how well a replacement part will match your dash. You can fairly easily get to the Headlight Override Switch at the bottom of the dash.
Race Director
Joined: Nov 2006
Posts: 12,937
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From: Sunshine Coast, Queensland, Australia
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Cruise-In VIII Veteran
Have you tryed pushing and pulling the over ride switch to see if that makes a difference?
Thread Starter
7th Gear
Joined: Jun 2025
Posts: 7
Likes: 0
Thanks for the response.
sorry for my delayed response. I had emergency eye surgery the day I posted and a\I haven’t been able to see.
The lights were working properly before disassembly.
i was able to see good enough to check things out today . One of the vacuum lines on the light switch was disconnected. I reconnected and the lights go up and down properly now. However, they are not illuminating.
i have a little more digging to do.
sorry for my delayed response. I had emergency eye surgery the day I posted and a\I haven’t been able to see.
The lights were working properly before disassembly.
i was able to see good enough to check things out today . One of the vacuum lines on the light switch was disconnected. I reconnected and the lights go up and down properly now. However, they are not illuminating.
i have a little more digging to do.
Thread Starter
7th Gear
Joined: Jun 2025
Posts: 7
Likes: 0
Thanks for the reply. Sorry for the delayed response. I had to have eye surgery the day I posted and just now see well enough to read your reply.
one of the vacuum lines was disconnected from the light switch. The lights go,up,and down as they should now however they are not illuminating.
one of the vacuum lines was disconnected from the light switch. The lights go,up,and down as they should now however they are not illuminating.
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Joined: Sep 2013
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Likes: 6,905
From: New Or-leens Loo-z-anna
Now would be a good time to put light relays in the under hood wiring harness.
Also run 2 sizes larger heavier gauge wires to the light bulbs.
You'll be amazed at how much brighter they will be...and the wiring will be updated in case you upgrade the light bulbs later.(per Forum members)
Also run 2 sizes larger heavier gauge wires to the light bulbs.
You'll be amazed at how much brighter they will be...and the wiring will be updated in case you upgrade the light bulbs later.(per Forum members)
Melting Slicks
Joined: Feb 2018
Posts: 2,295
Likes: 702
From: Marietta GA
Did you make sure that the thin metal Ground Strap from the light switch is you the speedometer. It’s been a few years since I pulled my speedometer and tach, but I am pretty sure the hound strap is necessary. By the way, the rest light switches are very hit or miss.