Headlight raises when engine is shut off
Thread Starter
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
Headlight raises when engine is shut off
Went for a drive today and when I shut off the engine one of the headlights popped up. I know I have seen a thread on this before, but I can't seem to find it. Any suggestions?
Pro
Joined: Apr 2005
Posts: 603
Likes: 2
From: Illinois, USA
Originally Posted by 70 LS1
Went for a drive today and when I shut off the engine one of the headlights popped up. I know I have seen a thread on this before, but I can't seem to find it. Any suggestions?
Brian.
:
Drifting
Joined: Nov 2002
Posts: 1,951
Likes: 1
From: Shore NJ
Sounds like your headlight vacuum valve and vacuum filter is leaking or shot, check that valve and filter, also check the vacuum hoses and fit with both. Heat and age dries the hoses and the diaphram in the valve, it's an easy fix, the a new vacuum valve will run you around $13-$15.00
Had the same problem awhile back.........
Had the same problem awhile back.........
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Originally Posted by 73jst4fun
Sounds like your headlight vacuum valve and vacuum filter is leaking or shot, check that valve and filter, also check the vacuum hoses and fit with both. Heat and age dries the hoses and the diaphram in the valve, it's an easy fix, the a new vacuum valve will run you around $13-$15.00
Had the same problem awhile back.........
Had the same problem awhile back.........
Pro
Joined: Jun 2005
Posts: 725
Likes: 1
From: FL.
I had the same problem, Lamp doors started opening on their own, I had to laugh, never seen anything like it before. Seems strange but GM designed the headlamp part of the system to default to open when there's low or no vacuum. That way, if your driving at night and have no vacuum, the doors dont close and you still have your headlights.
Your system is starting to leak, Its very hard to diagnose the culprit.I got a hose kit, replaced them all, but that wasnt the problem, turned out to be the vacuum relay up front between the headlamps. 70 bucks from Zips
Your system is starting to leak, Its very hard to diagnose the culprit.I got a hose kit, replaced them all, but that wasnt the problem, turned out to be the vacuum relay up front between the headlamps. 70 bucks from Zips
Thread Starter
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
Originally Posted by 69vettester
I had the same problem, Lamp doors started opening on their own, I had to laugh, never seen anything like it before. Seems strange but GM designed the headlamp part of the system to default to open when there's low or no vacuum. That way, if your driving at night and have no vacuum, the doors dont close and you still have your headlights.
Your system is starting to leak, Its very hard to diagnose the culprit.I got a hose kit, replaced them all, but that wasnt the problem, turned out to be the vacuum relay up front between the headlamps. 70 bucks from Zips
Your system is starting to leak, Its very hard to diagnose the culprit.I got a hose kit, replaced them all, but that wasnt the problem, turned out to be the vacuum relay up front between the headlamps. 70 bucks from Zips
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Instructor
Joined: Apr 2003
Posts: 144
Likes: 0
From: Neenah WI
this Thread is interesting as I just put out a Thread Friday simular to this.
One Simple Question I have, all these relays and check valves, anyone have pics of where they are? As in the key ones you are discribing. When I look and try to follow the vacuum hoses all I find is a mile or more of vacuum hose going all sorts of ways.
My Chevy book doesn't show the vette vacuum system..
Thanks
One Simple Question I have, all these relays and check valves, anyone have pics of where they are? As in the key ones you are discribing. When I look and try to follow the vacuum hoses all I find is a mile or more of vacuum hose going all sorts of ways.
My Chevy book doesn't show the vette vacuum system..
Thanks
Le Mans Master
Joined: Jun 2004
Posts: 9,289
Likes: 16
From: Skippack PA
St Jude Donor '13
I've lost count of the number of times I've posted this link and seen it posted. 
http://209.183.231.72/corvette-101/vacuum.htm
This is an excellent troubleshooting guide that will help you narrow down where the problem is.
http://209.183.231.72/corvette-101/vacuum.htm
This is an excellent troubleshooting guide that will help you narrow down where the problem is.
Instructor
Joined: May 2004
Posts: 119
Likes: 0
From: Getzville NY
Originally Posted by TheKomoman
I've lost count of the number of times I've posted this link and seen it posted.
http://209.183.231.72/corvette-101/vacuum.htm
This is an excellent troubleshooting guide that will help you narrow down where the problem is.
http://209.183.231.72/corvette-101/vacuum.htm
This is an excellent troubleshooting guide that will help you narrow down where the problem is.
Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
Drifting
Joined: Sep 2001
Posts: 1,427
Likes: 1
From: Boxford Mass
Originally Posted by Bullyj
Me too 
I have been thinking about this since last night, when the same thing happened on my car!
I'll confirm this tomorrow, but I suspect a partially bad headlight switch or valve under the steering column. These feed the actuator relay.
Thread Starter
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
Well, the check valve is bad. With the engine running, I pinched the line between the check valve and the engine. I then shut off the engine and released the clamp. PSSSSSSSSSSSS the vacuum was bleeding off. I then started it back up, pinched the line again, then shut it off again. After a few minutes I turned on the lights and they actually came up with the engine off. I have had my car for 6 years and they have never been able to do that.
Looks like I will be buying a new check valve.
Looks like I will be buying a new check valve.
Pro
Joined: Apr 2005
Posts: 603
Likes: 2
From: Illinois, USA
Originally Posted by 70 LS1
Well, the check valve is bad. With the engine running, I pinched the line between the check valve and the engine. I then shut off the engine and released the clamp. PSSSSSSSSSSSS the vacuum was bleeding off. I then started it back up, pinched the line again, then shut it off again. After a few minutes I turned on the lights and they actually came up with the engine off. I have had my car for 6 years and they have never been able to do that.
Looks like I will be buying a new check valve.
Looks like I will be buying a new check valve.
Pro
Joined: Apr 2005
Posts: 603
Likes: 2
From: Illinois, USA
Originally Posted by theandies
The first and best investment in troubleshooting the headlamp and wiper door vacuum system is a hand vacuum pump.
I bookmarked the page to dig into that ...thanks guys! Now I have just one more little (and probably expensive) project to work on.
