headlight bypass valve
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
headlight bypass valve
what's the purpose of the headlight bypass valve under the drivers side dash. all i can see it does is keep the headlight doors from operating. what's the point in that?
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
The point of the over ride is so you can raise the headlights without turning the lights on. This so you can change bulbs or wash the headlights and bucket.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by greyghost79
what's the purpose of the headlight bypass valve under the drivers side dash. all i can see it does is keep the headlight doors from operating. what's the point in that?
snow and ice can make it hard for the doors to pop open
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
The real purpose is to allow you to open the doors with the engine off. In an ideal world with no leaks, the vacuum canister will hold enough vacuum to raise the lights even with the engine off. I have never met anyone that can actually do this, though.
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Burning Brakes
Joined: Dec 2002
Posts: 1,205
Likes: 1
From: "Too Low, Too Fast, Too Loud" TX
Originally Posted by 70 LS1
The real purpose is to allow you to open the doors with the engine off. In an ideal world with no leaks, the vacuum canister will hold enough vacuum to raise the lights even with the engine off. I have never met anyone that can actually do this, though.
Instructor
Joined: Sep 2004
Posts: 168
Likes: 0
From: Houston Texas
I believe the plumbing is such that it is fail safe. The head lights come up with a loss of vacuum. I got rid of my switch. The vacuum lines were in the way when I would go under the dash. If I want to raise the headlights without the lights on I just disconnect the right vacuum line and bleed off the vacuum. I have it marked so I can remember which to disconnect.
I was trying to tidy up the engine compartment. I ran a single large vacuum hose from the manifold over the brake vacuum assist, teed to the vacuum assist and then under the left fender where with the right fittings I was able to connect all of the other hoses.
I was trying to tidy up the engine compartment. I ran a single large vacuum hose from the manifold over the brake vacuum assist, teed to the vacuum assist and then under the left fender where with the right fittings I was able to connect all of the other hoses.
