I'll bet I've spent 40 hours off and on trying to get there things to work. I have eventually replaced every part but the vacuum tank. Here's is what is happening. I have checked every part by itself and all SEEMS right. With everything hooked up if I turn on the headlights both doors open properly. BUT when I turn off the headlights they do not close. Here's the wierd part. If I leave the headlights ON, I can pull the hose coming from the headlight switch to the top of the vacuum switch and they will close, plug it back in and they will open ( this is with the headlight switch on during this process).
Does anybody have an idea of what is wrong. This is driving me crazy, I have worked through all the stupid mechanical issues with the doors, hoses etc and now everything opens and closes smoothly, but I am so close to finishing.

Thanks
Ray

I'll bet I've spent 40 hours off and on trying to get there things to work. I have eventually replaced every part but the vacuum tank. Here's is what is happening. I have checked every part by itself and all SEEMS right. With everything hooked up if I turn on the headlights both doors open properly. BUT when I turn off the headlights they do not close. Here's the wierd part. If I leave the headlights ON, I can pull the hose coming from the headlight switch to the top of the vacuum switch and they will close, plug it back in and they will open ( this is with the headlight switch on during this process).
Does anybody have an idea of what is wrong. This is driving me crazy, I have worked through all the stupid mechanical issues with the doors, hoses etc and now everything opens and closes smoothly, but I am so close to finishing.

Thanks
Ray

When you first start up the car, with the headlights off, do they open?

When you pull the top vacuum switch off and then plug that line, does it make a difference?

I just got mine working, first time in 3 years. All new hoses and the tank was vac checked then painted. Have you put a Vac guage on the hoses going to the lights when they are open and then turn off the switch to see if there is Vac going to them? I was as frustrated as you over the years but now Im thrilled they work finally. Any Vac leaks near the switch? They can be hard to hear wth the engine running, wipe some liquid soap around the connections and see if it gets sucked in? Just an idea.

When I first start up the car with headlights off the headlights do not open.

The only way I get them to close is to have the headlight switch on and pull the return hose from the headlight switch off of the vacuum switch.

If I monitor the hose from the headlight switch I get vacuum when the switch is on and none when the switch is off.

I have looked at the Vacuum switch and the plunger does move up and down to connect the red and green portion of the switch to the yellow when vacuum is applied to the headlight return (top of vacuum switch).

Thanks
ray

I am using a vacuum pump to test. I am subbing in the vacuum pump to the hose that comes out of the Manifold so I can hear for any leaks. I can take the large red and green hoses coming out of the vacuum switch loose and apply vacuum too each one and the lights open and close properly. I keep thinking (don't they have to vent the opposite side open of the what ever way your applying vacuum so it can pull in air) to allow the actuator to move?. Does the Vacuum switch open to allow outside air in.

Thanks
ray

When I first start up the car with headlights off the headlights do not open.

The only way I get them to close is to have the headlight switch on and pull the return hose from the headlight switch off of the vacuum switch.

If I monitor the hose from the headlight switch I get vacuum when the switch is on and none when the switch is off.

I have looked at the Vacuum switch and the plunger does move up and down to connect the red and green portion of the switch to the yellow when vacuum is applied to the headlight return (top of vacuum switch).

Thanks
ray

There is no return line from the headlight switch to the vacuum relay switch. The headlight switch only supplies vacuum to the vacuum relay switch or vents the vacuum off of the switch.

With the light switch off and the car running you should have vacuum to the top of the vacuum relay switch and vacuum in the green hoses (which should be connected to the rear of the actuators). With the headlight switch off you should have no vacuum at the relay switch (not only no vacuum but you should be able to suck air thru the line) and vacuum in the red hoses which should be connected to the front of the actuators)

Since the only way to get the headlight doors to close is to disconnect the line to the vacuum switch, it sounds like the headlight switch is cutting off vacuum, but not venting the line properly.

Disconnect the vacuum line to the headlight switch, and then use the override switch. Do the headlight doors work correctly when using the overrride switch only? If so the problem is in the headlight switch.

Hi Mark,

This is what I did. I disconnected the vacuum line that comes from the headlight switch and goes to the top of the vacuum switch ( nothing connected to the top of the switch).
I connected vacuum directly to the yellow ( center line) of the Vacuum switch).
Using the override switch I can move it from normal to open and nothing happens.

Hi Mark,

This is what I did. I disconnected the vacuum line that comes from the headlight switch and goes to the top of the vacuum switch ( nothing connected to the top of the switch).
I connected vacuum directly to the yellow ( center line) of the Vacuum switch).
Using the override switch I can move it from normal to open and nothing happens.

Check to see if your vacuum switch is porting from the center to either the upper or lower port. The opposite port should be connected to atmosphere (so you should be able to blow thru the un-connected port to atmosphere thru the filter at the bottom.
When I got mine working, it was after I did some probing into the ports and removed some plastic flashing.

They WORK, They WORK!!!!!!!!!


Thanks everybody for your help, After following everybodys advice and checking all the individual components, I tracked it down to the plunger in the vacuum switch was staying in the UP position (vacuum applied to top of switch coming from headlight switch) even after I removed vacuum by closing the headlight switch. This prevented the headlight from closing. In previous trouble shooting methods if I pulled that line off with everything running the doors would close.
This lead me to the headlight switch, theory was that after closing the headlight switch the line was retaining vacuum and not bleeding off to allow the spring loaded plunger to drop down. The switch must have a bleed off on one side or the other? My only theory at that point was I must be an idiot and reversed my vacuum lines going to the headlight switch. I switched them at the tank side to test and GUESS WHAT? I'm an idiot!!!

They WORK, They WORK!!!!!!!!!

Thanks to all

Ray

They WORK, They WORK!!!!!!!!!


Thanks everybody for your help, After following everybodys advice and checking all the individual components, I tracked it down to the plunger in the vacuum switch was staying in the UP position (vacuum applied to top of switch coming from headlight switch) even after I removed vacuum by closing the headlight switch. This prevented the headlight from closing. In previous trouble shooting methods if I pulled that line off with everything running the doors would close.
This lead me to the headlight switch, theory was that after closing the headlight switch the line was retaining vacuum and not bleeding off to allow the spring loaded plunger to drop down. The switch must have a bleed off on one side or the other? My only theory at that point was I must be an idiot and reversed my vacuum lines going to the headlight switch. I switched them at the tank side to test and GUESS WHAT? I'm an idiot!!!

They WORK, They WORK!!!!!!!!!

Thanks to all

Ray


Congrats to you Ray.
Pretty cool when you finally figure it out.

Hi Guys. I'm new to this web site and this is my first post here. I have been reading with interest this thread about RS vacuum headlight operation. I'll be back home to work on my '68 Z28 headlights in 3 weeks, and thanks to the "experts" here I should be operational shortly thereafter.My vacuum headlights have been giving me fits for longer than I'm going to admit in public. Thanks again for the useful tips.

Hi Zapper68,

Good luck on the headlights, If you have problems or questions email me and I'll try to help you while it's still fresh in my mind.

Ray