Testing headlight switch?
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,830
Likes: 20
From: Las Vegas Nevada
Testing headlight switch?
Hello everyone,
can anyone tell me the procedure to test the vacuum portion of the headlight switch for proper operation? The fingers that hold the vacuum port plate were not crimped well and when I was hooking the vacuum lines to the switch the plate fell off and with it came the rubber block, metal plate and spring in the switch.
I put the switch back together (I am 99% sure it is correct) but the headlights don't want to work?? Any way to test the switch with a vacuum gauge or???
Also, someone referred to a manual overide cable in another thread referring to the headlights. Where is this cable located??? I swapped out my dash for a new one, and had the problem mentioned above when I was putting the headlight switch in (new switch) and now the headlights don't work?
The car is a 1980.
Thanks!
can anyone tell me the procedure to test the vacuum portion of the headlight switch for proper operation? The fingers that hold the vacuum port plate were not crimped well and when I was hooking the vacuum lines to the switch the plate fell off and with it came the rubber block, metal plate and spring in the switch.
I put the switch back together (I am 99% sure it is correct) but the headlights don't want to work?? Any way to test the switch with a vacuum gauge or???
Also, someone referred to a manual overide cable in another thread referring to the headlights. Where is this cable located??? I swapped out my dash for a new one, and had the problem mentioned above when I was putting the headlight switch in (new switch) and now the headlights don't work?
The car is a 1980.
Thanks!
Last edited by VtVette; Dec 23, 2004 at 07:29 PM.
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 VtVette
Hello everyone,
Also, someone referred to a manual overide cable in another thread referring to the headlights. Where is this cable located??? I swapped out my dash for a new one, and had the problem mentioned above when I was putting the headlight switch in (new switch) and now the headlights don't work?
The car is a 1980.
Thanks!
Also, someone referred to a manual overide cable in another thread referring to the headlights. Where is this cable located??? I swapped out my dash for a new one, and had the problem mentioned above when I was putting the headlight switch in (new switch) and now the headlights don't work?
The car is a 1980.
Thanks!
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 VtVette
Thanks Bob, I saw that switch. How is it supposed to work? Never actually used it - never even knew it was there until I pulled the dash out.
when you pull it down it makes the headlight doors pop open....used for washing car, snow, ice etc.... not sure about this but i think the cars with wiper doors also have one for their wiper doors also....i can't explain how the vacuum system works and this explanation could be backwards, but there is always vacuum going to the headlight system in one way or another and when it gets "directed" or "removed" something happens...I think when that switch is pulled down it removes the vacuum from one side of the headlights relays and that causes the vacuum on the other side to be directed to open up the headlights.,..
Pro
Joined: Mar 2003
Posts: 708
Likes: 66
From: New Franklin, OH
Make sure you didn't swap the hoses to the switch, if I'm not mistaking it only operates in 1 way.
Check out this site, it might give some good tips:
http://209.183.231.72/corvette-101/vacuum.htm
Sonny
Check out this site, it might give some good tips:
http://209.183.231.72/corvette-101/vacuum.htm
Sonny
Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
The vacuum source feeds into the port on the lightswitch closer to the ****. The other port then goes to the override valve and finally to the headlight door relay valve.
The valve should pass vacuum in one position and block it in the other I don't know which is which. You can find out by pulling the pilot line off the headlight door relay and seeing if the lights go up. If so, then in the off position on the light switch the vacuum should be blocked, otherwise the converse is true.
I would GUESS that vacuum is needed to the headlight door relay to keep the headlights down.
My books show opposite of the site noted by the previous post, so I could be wrong here, although mine is plumbed per my books.
The valve should pass vacuum in one position and block it in the other I don't know which is which. You can find out by pulling the pilot line off the headlight door relay and seeing if the lights go up. If so, then in the off position on the light switch the vacuum should be blocked, otherwise the converse is true.
I would GUESS that vacuum is needed to the headlight door relay to keep the headlights down.
My books show opposite of the site noted by the previous post, so I could be wrong here, although mine is plumbed per my books.
