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Old Dec 13, 2017 | 01:04 PM
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Claudio Silvreti's Avatar
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Default Headlights problem

Hi, I have a problem with both headlights. The headlights do not go open, just 1 inch and close again. I checked the lines with the drawing and this seems ok. What or where is the problem? Can someone help me? Thanks a lot.
Claudio
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Old Dec 13, 2017 | 01:35 PM
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Originally Posted by Claudio Silvreti
Hi, I have a problem with both headlights. The headlights do not go open, just 1 inch and close again. I checked the lines with the drawing and this seems ok. What or where is the problem? Can someone help me? Thanks a lot.
Claudio

It's most likely a bad relay valve(s) because they don't last a very long time.
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Old Dec 13, 2017 | 02:01 PM
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Hi Claudio,
There are cars still have their original relays that operate fine.
What year is your car and how many headlight relays does it have?
Are both of the headlight doors acting the same?
Have the doors been operating properly until now?
The head-light switch in the dash controls both the electricity to the head lamps and the vacuum signal to the headlight relay (s).

Do the headlights illuminate as the door begins to open?
Do the headlamps remain illuminated after the door has close?
Have you tried to open the headlight doors using the vacuum override switch that's located below the steering column. It's the stalk to the left of the round ****.
Pulling it down should open the headlights open the headlights.
Try it.
Regards,
Alan



Here are the 2 relays located between the headlights on a 71 car. (The one on the left is partly hidden by the horn. Check that area on your car.


Last edited by Alan 71; Dec 13, 2017 at 02:04 PM.
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Old Dec 13, 2017 | 03:21 PM
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Hi Alan,
My car is a '76 and there are 2 headlight relays.
Yes, both of the headlight doors acting the same, opens for 1 inch and go down again. (I can push them open by hand.)
I know that head-light switch in the dash controls the electricity to the head lamps and the vacuum relays.
Yes, the headlights illuminate as the door begins to open.
When I bought the Corvette headlights were always open. The seller told me that there was a problem with the headlights but had no idea what it was.
When I had the car at home I pushed the override switch in. (This was out by the seller)
When turning off the headlights these went close.
Now the headlights illuminate, but do not go open.
All the hoses are new and properly connected as described in the manual.
Can it be a problem with a valve or filter? I do not know....
Regards Claudio
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Old Dec 13, 2017 | 03:41 PM
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Many time the seal (grommet) in the actuators goes bad.
Here's a how-to that shows all the parts and how to test them.

http://www.corvette-101.com/vacuum.htm
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Old Dec 13, 2017 | 03:44 PM
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Hi Claudio,
In order to determine what parts of the system are operating the way they're intended you really need a small vacuum pump with a vacuum gauge like a mity-vac (in the U.S.).

Do you have access to some sort of pump?

The fact that both doors operate in unison indicates to me that the problem is in the vacuum supply TO the relays. (If only one door was not working THAT would indicate it's the relay or actuator for that door. It seems unlikely that both relays would fail at the same time in the same way.)
What did you use as a guide when replacing the vacuum hoses?

This would lead me to believe it's a problem with the headlight switch.
You say you replaced the hoses... does this include the hoses under the dash to and from the headlight switch and over-ride switch?

Regards,
Alan

Last edited by Alan 71; Dec 13, 2017 at 03:46 PM.
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Old Dec 13, 2017 | 04:09 PM
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Hi Alan,
Thanks for your reply.
I dit not replaced the hose by myself, it was done in a garage.
I checked the hoses with the color codes on the basis of this drawing.
see annex. It seems that the hoses at the switches also are new.
I have no vacuum pump. I'll check tomorrow everything with your advice.
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Old Dec 13, 2017 | 04:15 PM
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Is the engine running when you try to open the headlights? If not, start it and try them.
Good luck!
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Old Dec 13, 2017 | 04:18 PM
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Yes, engine is running at 800 rpm.
Regards, Claudio
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Old Dec 14, 2017 | 04:36 PM
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Hello,
Today everything tested, using a vacuum cleaner. The relays and switches work perfectly. Problem is a leak in the actuator on the passenger side. This can only close. Has no power to push open. There is a leak I can hear. Now I am thinking to replace the rubbers in the actuator.
Best Regards, Claudio
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Old Dec 14, 2017 | 06:31 PM
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It might be the seal(grommet) or the diaphragm.
Test :

http://www.corvette-101.com/vacuum.htm
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Old Today | 04:13 AM
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Default Headlights opens and closes immediately

Originally Posted by Claudio Silvreti
Hi, I have a problem with both headlights. The headlights do not go open, just 1 inch and close again. I checked the lines with the drawing and this seems ok. What or where is the problem? Can someone help me? Thanks a lot.
Claudio
I have had this problem too. The reason was a worn sealing of left activator.
if activator wants to raise the headlight up, its rod is moving out, it comes to a position where the sealing was worn out. Thus the vacuum drops and the lid closes. Installing new sealing kits on both activators make it work.


Last edited by FlashJack; Today at 04:14 AM. Reason: Typing mistakes
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