chstitans42

Heres the story.
So i have the car running, and i turn the headlights on. The drivers side headlight pops up when turned on, and goes back down when turned off. Passenger side...nothing.I figure its a vacuum line or actuator problem. easy fix right?
Then when i pull the little headlamp panel control **** on the underside of the dash, the passenger side headligh pops up when turned on, and goes back down when turned off. Drivers side...nothing.

So maybe im just ignorant with the vacuum process on these headlights. They each go up and down prefectly fine, just each side uses a different switch to operate. Any light on this problem would be great.

I have a 75 by the way...

Ray Y

Sounds like you have a vacuum line crossed, not an actuator problem. Did this problem just start out of the blue, or did you change something and then it occured?

I was in Dallas on Tuesday, a little breezy but nice Vette weather.

Vette Gator

This is pretty weird, since the vacuum part of the two switches are in series. There should be one small control line that T's off to the two vacuum relays just in front of the hood. This makes them both go up and down together. Was the vacuum system bubba'd so that separate control lines go to the two relays? Offhand, this is about the only way I could explain your observations.

copter

I've got the same problem except I have to pull my lights up manually.The go down fine.They worked good when I bought it and I haven't touched it so if you don't mind Ill just

jdp6000

This may help. You have something crossed...most probably the hoses identified by red and green.

surgn

Excuse me for bumping in on this post, but i have a similar problem. I have an 81 and the headlights go up when they are turned on- well sort of, the left goes up smooth and the right one goes up real slow, but speeds up once the left on is fully up. Then when turn off the lights, the left one goes down fine while the right one doesn't and i have to push it down myself or even hit the arm underneath with a mallet.

Any suggestions? thanks and sorry for butting in.

jdp6000

It probably the seal at the front of the actuator. It is know to wear out. If you look up from under the front end you will see an accordian shaped rubber boot on the actuator rod on the actuator. Under that boat there is a seal. If the seal tears or gets a small hole the air pressure in the actuator leaks out.

You can tes for it. My way is primative but works. Open the hood. Disconnect the hose (identified as green above) from the relay and gently blow into it or suck on it. The ehadlights will go up or down depending on your action. There should be resistance. If you blow or suck and there is no resistance the boot is ripped. Eckler has a kit for about $10 bucks. Search under "actuator seal".

im

gliot1

It is my understanding that vacuum holds the lights down and lack of vacuum allows them to rise. I believe there are springs which cause the rising action. Could it be the mechnism is somehow mechanically "seized" down? Could you not swap the vacuum from R to L? If the smae light does not work, then you know it is the mechanical mechanism. If it works then you have a vacuum issue.

surgn

Nice- I'll try both. Thanks guys- easy tests that I wouldn't have thought of....

redwingvette

Not true. Not knocking you but what happens is the vacuunm shifts when you pull the light switch or override switch which activates a relay that allows vacuum to make them go up/down. The springs only help lock them into the up position.

copter

Thanks for the diagram.Can you tell me whats wrong when the overide switch don't work?

Red70vette

The only way to solve vacuum problems is to understand the vacuum system and trouble shoot it one system at a time. Here is a website with a great explaination of the system: http://vetteworks.tripod.com/techdocuments/Vaccum.html

jdp6000

Its probably been bypassed or the lines are reversed. Common problem. On my old vette i purposely reversed my line. It allowed me to turn the headlights on with the doors in the down position. It lit up through the front grills...looked like fog lights.

The routing is as simple as it looks in the diagram. Drop the panel under the steering wheel to get access to the pull down. Look at the lines and see if the match up with what you see in the diagram.

Jim

jdp6000

Nice link!!!Saved that one.

Thanks,
Jim