My headlights won't go up when you pull out the light switch. They will only work when you pull down the bypass. Every piece in the system is new, all the vacuum lines are set up as per the schematic. Any ideas.

 

Have you read this post?

https://www.corvetteforum.com/forums...tem-works.html

From what I can tell, when either the bypass or the headlight switch is pulled, vacuum is removed from the line running to the relays. The symptom you describe would almost indicate the switch is bad, but you said all components are new? Have you tried removing the switch from the loop altogether (connecting the hoses that normally go to the switch together), or tried removing the line from the switch to see if the headlights go up then?

I'm not sure it makes a difference, but have you tried swapping the two lines that go to the switch?

 

Headlight switch is new, but dosen't mean it can't be not working. I went thru the system and it seems to be hooked up correctly. I will try the things you suggested today, thanks for the reply.

 

When we bought our car, the headlight switch was bypassed and the only way to get the lights up were the bypass switch. I rerouted all the hoses this winter, and just recently got the car on the road found out my switch must be bad, at least when I pull our switch I hear sucking, If you have the hoses connected the way these diagrams show, it would be safe to say the switch might be the culprit. Willcox has a nice video on Youtube that shows how to test the switch with a basic vacuum tester you can buy at harbor freight.

 

In the [difficult] process of installing the new headlamp switch, one of the vacuum tubes may have been dislodged....hence, the 'sucking' noise.

 

I only hear the sucking noise when I pull the switch to on.

 

Took the hoses off the headlight switch and everything worked good with just the bypass. I bought a new headlight switch online and should have it next week.

 

I put my new switch in, lights wouldn't go up, pulled the bypass, lights went up, pulled the light switch lights went back down with lights on. Checked the hoses as per a diagram I got from Wilcox, everything seemed right. Oy

 

I then switched the hoses at the light switch just in case, I could then get the lights up with the bypass lights on with the switch but then heard sucking sound out of the light switch, how annoying

 

Me thinks you almost jinxed me! I'm half way thru my interior/dash install, and had installed my headlight switch a few days ago. Tried out the headlights today, and they were acting very strange (opening/closing slowly, and not at the same time). Turned out to be the lines at the headlight switch being reversed (so it does matter).

Looking at the diagrams, the next thing I would try is to remove the bypass switch, and see what happens then. Make sure the rear port on the switch runs to the relays. Other than that, I would double and triple check that the hoses are connected right....if pulling the headlight switch when the bypass is pulled made the headlights go down, then the bypass switch is still allowing vacuum to reach the relays (when the bypass is pulled, it should be impossible for vacuum to reach the relays, regardless of the headlight switch position).

Hope this helps. I'm definitely not an expert with these things...

 

Bad headlight switch. This was a new switch. Never worked the way it was supposed to. I bought it when I bought all the components to do the headlights over.

 

I cannot believe the crappy quality of todays repo parts!!! I am spoiled, because I bought mine from GM years ago. I keep hearing about the headlight switches, power window switches and even the vacuum relays being bad. And they are not cheap! Lou.