Posing another headlight problem
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Joined: Nov 2006
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From: Linden NJ
Posing another headlight problem
Have a 1972 Corvette. Each time i start the car, my headlights pop up. I have the routing and troubleshooting book, all the hoses seem to be hooked up and in good shape. The headlights will not go down on their own either after i turn off the engine. I was just wondering if anyone out there has had a similar problem and can point me in the right direction as to a possible fix or where to look. The lights have always worked well in the past until this year. Yes, i can turn the lights on, and yes i have checked the manual overide switch for malfunction and it is not in the overide position.
Thanks in advance for any ideas.....Ron
Thanks in advance for any ideas.....Ron
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Joined: Nov 2006
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From: Linden NJ
No, mine move easily up and down, only problem is when i 1st start engine the headlights pop up but they do not go down when i turn off the engine.
No vacuum leaks either, checked entire system and hoses fairly new as well.
No vacuum leaks either, checked entire system and hoses fairly new as well.
Race Director
Joined: May 2006
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From: Dayton, Ohio
Your not getting vacuum on the small white stripped hose going out to the relays between the headlights.Do you have your pulldown pushed in?
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Race Director
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From: Dayton, Ohio
Drifting
Joined: May 2005
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From: Somers CT
I agree, replace the check valve in the main vac line.
http://www.ecklers.com/product.asp?p...7&dept_id=1326
http://www.ecklers.com/product.asp?p...7&dept_id=1326
Le Mans Master
Joined: Jan 2006
Posts: 8,319
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From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
I agree, replace the check valve in the main vac line.
http://www.ecklers.com/product.asp?p...7&dept_id=1326
http://www.ecklers.com/product.asp?p...7&dept_id=1326
Pro
Joined: May 2007
Posts: 593
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From: Warrenville IL
My '75 has a similar issue. I've isolated it to two items, the override valve and the main switch.
My override valve was shot. When I replaced it I also put some rtv on it to make sure I had a really good seal. The issue got better.
The main switch in the dash is also an issue. I ran into a guy who was buying his 2nd replacement switch for his '74. He showed me the switch. It had two parts that appeared to be pressed together (top and bottom I think). On his previous 2 switches that press fit had failed so this time he was going to put some rtv on the seam to make sure it stayed sealed.
My override valve was shot. When I replaced it I also put some rtv on it to make sure I had a really good seal. The issue got better.
The main switch in the dash is also an issue. I ran into a guy who was buying his 2nd replacement switch for his '74. He showed me the switch. It had two parts that appeared to be pressed together (top and bottom I think). On his previous 2 switches that press fit had failed so this time he was going to put some rtv on the seam to make sure it stayed sealed.
Drifting
Joined: Apr 2008
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From: Lewisburg WV
thegazman
You mentioned that your lights do not go down when you turn off the engine. What might help you with trouble shooting to understand that vacuum closes the headlights and lack of vacuum allows them to spring open. If they are closed when you shut the engine off and open after the car sets for awhile your check valve is probably leaking air into the vacuum system. The reason the lights close with vacuum is to allow you to still have headlights at night if a hose came of or something breaks in the vacuum system. It would be tough driving on a curvy road at night and all of sudden your lights closed.
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Joined: Nov 2006
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From: Linden NJ
Fixed the problem. Had no vacuum at the headlight switch. Routed a new hose w/ vacuum to the headlight switch, it cured the problem. Headlights work fine now!
thanks all for the input.
thanks all for the input.
Melting Slicks
Joined: Feb 2006
Posts: 2,092
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From: Fayetteville Arkansas
you lucky dog.... ha ha... i still can't figure out what is wrong with mine... mine is doing the same thing where the headlights pop up upon starting the car without pulling any switch... and do not go down when I do pull the switch and then push it back in....although I did find that my check valve is bad, but from what I understand with the vac system that would not be the cause of the small white vac line not sending vacuum to the relay and causing the headlights to pop up... I guess i will have to pull my headlight switch again and check the vacuum there like MAILBOX1024 did... any other ideas????
thanks
sully
thanks
sully
Last edited by Sully1882; Jun 18, 2008 at 06:55 PM.
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From: Linden NJ
Actually i found mine by accident. When i was looking under the dash at the manual switch, i unplugged the vacuum ports at both ends of the manual over ride and i put them together. The headlights instantly dropped down and went back up when i unplugged the vacuum. This told me i was not getting vacuum at the headlight switch. I removed the dash to get access to the headlight switch, found no vacuum at either port. So i installed a T fitting and tapped into the wiper door vacuum, (which was eliminated when i bought the car a few years ago anyway), and then the headlight switch activated the headlight doors upon my command and not when i start the engine.
Just lucky i guess.
Ron...NJ
Just lucky i guess.
Ron...NJ
