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Old Jul 17, 2017 | 11:29 AM
  #1  
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From: chico ca
Default Headlight Help

On my 68 vette right headlight goes up and down with a little clunk, put my left only goes up 1/2 way and goes down. Any suggestions?
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Old Jul 17, 2017 | 11:43 AM
  #2  
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From: mount holly NC
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Default Hi and welcome.

Many times the seal (grommet) in the actuator needs to be replaced.
Here's how to test and repair the parts.
http://www.corvette-101.com/vacuum.htm
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Old Jul 17, 2017 | 12:49 PM
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Hi B,
Welcome!
To help you determine what may be causing the problem with your headlights may be perhaps you might want to try this test while you're going over the information that Pb led you to.

Between the 2 headlight actuators (the cans shaped like 2 pie plates) are 2 vacuum relays (1 small hose and 3 large hoses on each). These direct a vacuum signal to each actuator to open or close the doors.

Carefully move the large red and green hoses from one side's relay to the same position on the other relay.
When all 4 hoses have been moved start the engine and pull the head light switch.
If the left side now opens and closes, but the right side doesn't, this indicates a problem with the left side relay. But, if the left side still doesn't open and close properly this indicates it's a problem with the left side actuator.

Perhaps you may want to give it a try?
Regards,
Alan

These photos show the 2 relays in the center and the actuators on each side. Move the red and green hose from one relay to the other.




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Old Jul 24, 2017 | 05:38 PM
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Originally Posted by Buttersvette
On my 68 vette right headlight goes up and down with a little clunk, put my left only goes up 1/2 way and goes down. Any suggestions?
Alan is a great mentor regarding these things.

Willcox also has a good diagram :-)






Last edited by caskiguy; Jul 25, 2017 at 10:56 AM. Reason: Add information
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Old Jul 24, 2017 | 06:34 PM
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Vetteworks.tripod.com to fully understand the whole vacuum system
Decent reference, but as is typical of many vacuum diagrams out there, the control circuit at the headlight switch and headlight override are switched. Plumbed this way, the headlights would not work. Vacuum source always goes to the vacuum port closest to the pull ****.
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Old Jul 24, 2017 | 07:28 PM
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Originally Posted by Dave J
Decent reference, but as is typical of many vacuum diagrams out there, the control circuit at the headlight switch and headlight override are switched. Plumbed this way, the headlights would not work. Vacuum source always goes to the vacuum port closest to the pull ****.
Interesting.
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Old Jul 25, 2017 | 10:54 AM
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Originally Posted by Dave J
Decent reference, but as is typical of many vacuum diagrams out there, the control circuit at the headlight switch and headlight override are switched. Plumbed this way, the headlights would not work. Vacuum source always goes to the vacuum port closest to the pull ****.
Ok, now I see the error in the drawing. Thanks for pointing that out.
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Old Jul 25, 2017 | 11:58 AM
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You're welcome!
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