Headlight opening troubleshooting 101
Thread Starter
Pro
Joined: Oct 2015
Posts: 651
Likes: 45
From: Raleigh area, NC
Headlight opening troubleshooting 101
Just picked up a 75 coupe last month. Headlights light can see them through the grills but no movement.
Any links or tips for troubleshooting? Why the heck did they change from C2 electric motor to vaccuum !
Any links or tips for troubleshooting? Why the heck did they change from C2 electric motor to vaccuum !
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Opening and closing the headlight doors is 100% vacuum. If they do not open with the headlight switch, try the over ride. If both fail, raise the hood and check the vacuum source on the rear of the intake manifold.
Thread Starter
Pro
Joined: Oct 2015
Posts: 651
Likes: 45
From: Raleigh area, NC
Only had it a month but has not worked, have not yet looked at the hoses or checked for vaccuum leaks.
So should I just check to see if all attached, pull actuator end off and check for airflow?
Where are the overriders?
Thanks.
So should I just check to see if all attached, pull actuator end off and check for airflow?
Where are the overriders?
Thanks.
Team Owner
Joined: Sep 2006
Posts: 31,200
Likes: 4,287
From: Westminster Maryland
Hi pmr,
Here's the typical location, below the steering column, for the headlight vacuum override switch.
Do you have an Assembly Instruction Manual and/or Chassis Service manual for your car?
Regards.
Alan
Here's the typical location, below the steering column, for the headlight vacuum override switch.
Do you have an Assembly Instruction Manual and/or Chassis Service manual for your car?
Regards.
Alan
Last edited by Alan 71; Feb 8, 2017 at 11:11 AM.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Dr. Detroit
Joined: Mar 2012
Posts: 10,095
Likes: 4,025
From: New Braunfels Texas
In the winter of 15', I had a guy bring me a 76' with non operational light doors.......half of the hoses were missing and the other half dry rotted. I replaced 22 feet of hose and they worked again.
But as posted....check the hose from the manifold and trace it back.
Here is a schematic.............
Jebby
But as posted....check the hose from the manifold and trace it back.
Here is a schematic.............
Jebby
Drifting
Joined: Jul 2006
Posts: 1,259
Likes: 154
From: Deplorableville Nebraska
Jebby,
The Vetteworks schematic is wrong. The headlight and headlight override hoses are reversed. Vacuum source hose always goes to the port closest to the pull ****. The first schematic is correct.
The Vetteworks schematic is wrong. The headlight and headlight override hoses are reversed. Vacuum source hose always goes to the port closest to the pull ****. The first schematic is correct.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Dr. Detroit
Joined: Mar 2012
Posts: 10,095
Likes: 4,025
From: New Braunfels Texas
Jebby
Le Mans Master
Joined: Aug 2006
Posts: 7,419
Likes: 1,555
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Your 75 does not have the wiper door.
Using this diagram and start by making sure your vacuum fitting on the manifold (behind your carb) is connected and then go step by step testing all the parts.
http://www.corvette-101.com/vacuum.htm
Using this diagram and start by making sure your vacuum fitting on the manifold (behind your carb) is connected and then go step by step testing all the parts.
http://www.corvette-101.com/vacuum.htm