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Why are my headlights doing this?

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Old Sep 22, 2003 | 08:58 PM
  #1  
vetnut72's Avatar
vetnut72
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From: Medley Fl
Default Why are my headlights doing this?

Wonderful forum!!!!!!! I'm glad to be a part of it!

I was rapidly accelerating onto the interstate today and noticed that at around 50MPH the headlights poped up on their own! I let off the gas and down they went.
They work great otherwise, and I've never noticed this before. The open within 1 second of each other when I turn them on, and close about the same time on shut off.
Any idea what gives?
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Old Sep 22, 2003 | 09:07 PM
  #2  
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From: CORTLANDT MANOR NY
Default Re: Why are my headlights doing this? (vetnut72)

Welcome to the wonderful world of Corvette headlight and wiper vacuum systems.

You have a vacuum leak and when you accellerate it draws the vacuum causing the headlights to pop open.

Check all your hose connections to make sure they are good and tight. Check your manifold vacuum pressure to make sure it is good and steady.

Then do a goggle search for Corvette vacuum systems there are some good websites devoted to the subject.
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Old Sep 22, 2003 | 09:35 PM
  #3  
sewright's Avatar
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From: pittsburgh PA
Default Re: Why are my headlights doing this? (BUGGSY1970)

http://www.corvettefaq.com/ has some info on the vacuum systems. What a royal pain that system is. A ridiculous amount of vacuum hoses running everywhere. One of the most annoying design features I've seen on a corvette...
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Old Sep 22, 2003 | 11:34 PM
  #4  
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From: St. Charles IL
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Default Re: Why are my headlights doing this? (vetnut72)

Good advice others had, check for vacuum leaks. You could also have a bad check valve. It's located near the brake booster. has one connection from the manifold, and 2 on the other side for headlight and HVAC controls.
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Old Sep 22, 2003 | 11:40 PM
  #5  
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wombvette
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From: New Hill NC
Default Re: Why are my headlights doing this? (Big Fish)

Probably a bad check valve, but is definitely caused by low vacuum in the signal circuit. When the vacuum falls out there, the lights default to open for safety.
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Old Sep 23, 2003 | 08:00 AM
  #6  
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vetnut72
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From: Medley Fl
Default Re: Why are my headlights doing this? (wombvette)

OK---It seems like a vacuum leak issue.

Thank you all!
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