81 headlights stuck in up position
Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
81 headlights stuck in up position
Just bought an 81 and the headlights are stuck in the up position. Previous owner thought it may need new actuators. So I didn't beet around the bush and replaced all the components. Actuators / Actuator relays / check valve and headlight switch. Lights still stay in the up position ???? I've checked and double checked the lines to make sure they were in the correct position and all is good...... What am I missing????`
Last edited by Troy Driver; May 13, 2014 at 01:30 AM.
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
Le Mans Master
Joined: Aug 2006
Posts: 7,427
Likes: 1,560
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
you need to determine if you have a mechanical issue ?... or a vacuum control issue ?
if you pull the vacuum lines off of the headlight actuators, then you can manually move the individual headlight bucket up and down,
via the actuator rod, Not the bucket.
when the they go up, they pass thru a camed overhinge, which is backed by a spring. and lock into the upright postion,
very carefully (don't pinch your fingers) you should be able to manually push the actuator rod fully down, and fully open,
releasing them from upright postion will require a bit more push on the rod, to get past the spring cam over. good luck...
if you pull the vacuum lines off of the headlight actuators, then you can manually move the individual headlight bucket up and down,
via the actuator rod, Not the bucket.
when the they go up, they pass thru a camed overhinge, which is backed by a spring. and lock into the upright postion,
very carefully (don't pinch your fingers) you should be able to manually push the actuator rod fully down, and fully open,
releasing them from upright postion will require a bit more push on the rod, to get past the spring cam over. good luck...
Last edited by 69Vett; May 13, 2014 at 11:12 AM.
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
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
"the Plunger" is a vacuum control switch directly under the steering wheel dash.
It is a head light override switch, which commands them them to stay up.
it pushes in, or pulls out, pulled out commands headlights up, pushed in is normal mode.
in normal mode when you turn on the light switch the headlights should open and close, with the light switch.
if the override under the dash is pulled out, ...headlights stay up.
It is a head light override switch, which commands them them to stay up.
it pushes in, or pulls out, pulled out commands headlights up, pushed in is normal mode.
in normal mode when you turn on the light switch the headlights should open and close, with the light switch.
if the override under the dash is pulled out, ...headlights stay up.
Burning Brakes
Joined: Aug 2009
Posts: 941
Likes: 3
From: Columbus OH
There are adjustment screws on the outer frame on each of the headlights.
As the lights go up, these adjustment screws press in to the frame and provide the opposing force to "lock" the cam action hinge in to place.
With the car off, crawl under the car, pull down on the hinge to collapse the light. (be careful not to pinch yourself, you will need to pull reasonably hard.) look for the adjustment screw closest to the fenders on each side and turn them in to shorten its length. It is creating too much pressure and the actuator can not overcome it. A lot of people think the screw adjustment has to lock HARD to keep the lights from going down when they encounter head wind at highway speeds... they are incorrect. only a quarter turn past "initial" surface contact is needed.
As the lights go up, these adjustment screws press in to the frame and provide the opposing force to "lock" the cam action hinge in to place.
With the car off, crawl under the car, pull down on the hinge to collapse the light. (be careful not to pinch yourself, you will need to pull reasonably hard.) look for the adjustment screw closest to the fenders on each side and turn them in to shorten its length. It is creating too much pressure and the actuator can not overcome it. A lot of people think the screw adjustment has to lock HARD to keep the lights from going down when they encounter head wind at highway speeds... they are incorrect. only a quarter turn past "initial" surface contact is needed.
Last edited by hyteck9; May 13, 2014 at 11:42 AM.
Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
stuck lights
Thank you all for the help. I am able to lower the lights manually if I disconnect the vacuum line from the check valve. The plunger is in the up position. And the headlight switch is off. But when I hook the vac line back to the check valve the lights pop up. Do plungers go bad????
Pro
Joined: Aug 2013
Posts: 591
Likes: 3
From: Monroe Washington
Here's the Wilcox technical data sheets I have been using to sort out a LOT of my issues... VERY INFORMATIVE!
http://willcoxcorvette.com/repairand...a638e6eced32b8
http://willcoxcorvette.com/repairand...a638e6eced32b8
Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
Stuck Lights
Here's the Wilcox technical data sheets I have been using to sort out a LOT of my issues... VERY INFORMATIVE!
http://willcoxcorvette.com/repairand...a638e6eced32b8
http://willcoxcorvette.com/repairand...a638e6eced32b8
Pro
Joined: Aug 2013
Posts: 591
Likes: 3
From: Monroe Washington
The stock system works fine, once you troubleshoot your issue... And I thought you JUST replaced all the stock hardware... Are you going electric motors after all that time and money because you can't get em to work yet? There are still other things to check on your stock system that may be simple to fix now that you've done the rest ... Such as vacuum lines collapsing under pressure and not allowing the canisters/actuators to do their thing...
This is the first I've read if going electric motors for your situation... Or did I miss something?
Duh... Just re- read your post... I'm sure you can get the stock setup to work... I know I would after all you've done already ... It would be a battle I would REFUSE to lose at this point. Lol
This is the first I've read if going electric motors for your situation... Or did I miss something?
Duh... Just re- read your post... I'm sure you can get the stock setup to work... I know I would after all you've done already ... It would be a battle I would REFUSE to lose at this point. Lol
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Here is everything you need to know to understand how the system works:
http://forums.corvetteforum.com/c3-t...tem-works.html
I guess there's nothing wrong with electrical actuation, per se, but it sure seems like an awful lot of time, money, and effort for a system that won't work any better than the stock system.
Scott
http://forums.corvetteforum.com/c3-t...tem-works.html
I guess there's nothing wrong with electrical actuation, per se, but it sure seems like an awful lot of time, money, and effort for a system that won't work any better than the stock system.
Scott
Safety Car
Joined: Nov 2008
Posts: 3,720
Likes: 557
From: Seattle Washington
Back when I replaced all the vacuum lines on my 1980 I ordered a kit and a very large drawing showing the color coded lines. As I am the original owner I know that my original lines had never been messed with. The Drawing was wrong with its codes for the Actuators them selves. It would of been correct for a pre 1980, but not for a 80-82. Its been a decade or more since I did it so It's a bit foggy on what the difference is. I think the Vacuum canisters are reversed or something from the previous years.
An easy way to trouble shoot the system is to take a long hose from another vacuum source than Your Engine. This way You can listen for leaks. In your case though you have replaced everything so most likely something is hooked up wrong, probably before you. Take the temporary Vacuum line and hook it up directly to each headlight assembly and see if they work. I'll bet they do. Then just start working your way back to the Engine source.
An easy way to trouble shoot the system is to take a long hose from another vacuum source than Your Engine. This way You can listen for leaks. In your case though you have replaced everything so most likely something is hooked up wrong, probably before you. Take the temporary Vacuum line and hook it up directly to each headlight assembly and see if they work. I'll bet they do. Then just start working your way back to the Engine source.
Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
Thank you to all... this forum rocks
Back when I replaced all the vacuum lines on my 1980 I ordered a kit and a very large drawing showing the color coded lines. As I am the original owner I know that my original lines had never been messed with. The Drawing was wrong with its codes for the Actuators them selves. It would of been correct for a pre 1980, but not for a 80-82. Its been a decade or more since I did it so It's a bit foggy on what the difference is. I think the Vacuum canisters are reversed or something from the previous years.
An easy way to trouble shoot the system is to take a long hose from another vacuum source than Your Engine. This way You can listen for leaks. In your case though you have replaced everything so most likely something is hooked up wrong, probably before you. Take the temporary Vacuum line and hook it up directly to each headlight assembly and see if they work. I'll bet they do. Then just start working your way back to the Engine source.
An easy way to trouble shoot the system is to take a long hose from another vacuum source than Your Engine. This way You can listen for leaks. In your case though you have replaced everything so most likely something is hooked up wrong, probably before you. Take the temporary Vacuum line and hook it up directly to each headlight assembly and see if they work. I'll bet they do. Then just start working your way back to the Engine source.
Thank you to all... this forum rocks
Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
The stock system works fine, once you troubleshoot your issue... And I thought you JUST replaced all the stock hardware... Are you going electric motors after all that time and money because you can't get em to work yet? There are still other things to check on your stock system that may be simple to fix now that you've done the rest ... Such as vacuum lines collapsing under pressure and not allowing the canisters/actuators to do their thing...
This is the first I've read if going electric motors for your situation... Or did I miss something?
Duh... Just re- read your post... I'm sure you can get the stock setup to work... I know I would after all you've done already ... It would be a battle I would REFUSE to lose at this point. Lol
This is the first I've read if going electric motors for your situation... Or did I miss something?
Duh... Just re- read your post... I'm sure you can get the stock setup to work... I know I would after all you've done already ... It would be a battle I would REFUSE to lose at this point. Lol