I'm sure this subject has been talked to death. BUT, i bought the assembly manual, the service manual, the electrical manual, and the unit repair manual. None of them shows me how the headlights go up and down. is there a description of how they work? or a video? Mine work, but are slow and go at different speeds. I know they sell the rebuild kits and the new actuator's, but i would like to understand how and why they go up and down.

The headlights operate on vacuum. The actuators(large round pie pans) have two separate chambers in them, one for opening, and one for closing the lights. When vacuum is supplied to one side of the actuators, the headlights are raised. Vacuum on the other side closes the lights. The vacuum relay valves control which side of the actuators get vacuum.
Slow acting headlights is a sign of a vacuum issue. Finding where that problem is is the hard part. I can send you some vacuum troubleshooting info that will help both to find the problem, and learn how the system operates.

I was looking at his car stats has an upgrade ZZ4 did we not have some discussion on post with certain engine configurations to double check where vacuum is taken from, and with cams change to availability of vacuum? just to get a conversation going?

I do notice if i rev up the engine the headlights work better. all the hoses were changed. Is there a vacuum canister or reserve vacuum chamber? there seems to be one under the brake boost. I was hoping the books i bought would explain how they work, but they don't say much about it? I tried searching for a forum on it but didn't find much.

The canister under the brake booster is probably the chacoal canister for the vapor recovery system and not a vacuum canister.  I see your vette is a 77 and Im not sure about 77s but I believe the 76 vacuum canister was welded between the frame rails, actually a part of the frame on the extreme front of the frame. Start following the vacuum lines from the connections of the two relays and see where they lead you.  I have a great PDF file of how the system works but dont know I can get it to you without a email address.  If you send me your email by PM then Ill be glad to send you the PDF file.  In the meantime check out http://www.corvette-101.com/ Click the "vacuum trouble" link on the left. Crossfire19822011-04-11 09:30:30

I e-mailed the "Vac 101" info already. I do have more stuff, but didn't send it at the time.
You could add a vac. reservoir if ya wanted...and could find room for one. Another option on engines that don't produce enough vacuum is to go with an electric pump...
 

OK, I found the link for the article that may be helpful.  The diagrams here are excellent.  http://fedbizoppssearches.com/CFImages/HeadlightVacuumTutorial.pdf

Joel,

Hey Scott..you will learn to love those headlight and vacuum system in your car..one thing that I learned fast was that once the vacuum system is leak free and works normal..was that my headlights came up at a little different time..about a second apart..I am a little OCD so I had to fix it...I found that one hose for the actuator was about 2 inches longer..had been changed at some point..that small difference in hose length changed the time in which it applied vacuum to the actuators..so now I got them down to a half tick..almost exactly the same time now..don't worry..there are plenty of other things with the vacuum system that will give you a happy feeling..do you know how much vacuum your engine produces? ? I just got a nice vacuum gauge from the white truck for less than 30$..if you don't ha e one already..it was actually made for carburated cars..have fun!

Rich