Mine have the same problem.  It's in the vacuum system.  I need both canisters and both filters, as well as a hose kit, but mine have never worked.  The PO didn't bother to keep up the system.

Joel or Ken will be able to tell you where to start.  If you have a vacuum pump/guage and know how to use it, you will be miles ahead.  It could also be one of the filters/valves by the firewall (Round disc usually white with 2 lines on one side and one on the other) or the lines under the dash to the lightswitch.  You could check there first.  If one line came off it might have loosened the other one.  That's a cheap check and will buy time till the guys get back from Pigeon Forge.

There is a publication out called Troubleshooting the '68 to '82 Corvette headlight and windshield wiper door vacuum system by Frank C Prow II, Copyright 1995 by Mid America Designs, Inc.  You might check Amazon or Ebay.

Dennis

Yep it's definately a case of elimination.  you've probably just got a leaking hose or valve somewhere.  Just hope both actuators haven't gone west.

Chips hit it on the nose. All I needed was to cut the very tip of the hose attached to the actuator and BINGO!. It had a number of small cracks. Luckily, there was enough slack to do so. Good luck.

JR

Chris Prow....IS A MEMBER of this forum....not extremely active YET due to the normal crap that comes up in life.... BUT to my understanding he honestly got burned by MAD...(they sold his work but deglected to follow up on the $$$$ or whatever....My impression of the situation which may or may not be the actual case..)

But a PM directly to him should get you a copy of his "little" troubleshooting guide if you can not find it...

I think he now lives in Tenn...Not sure.

Bob

If boath are getting the same vacume and only one opens it may be the actuator seal around the pushrod. If you plug the line of the one that doesn't work, turn on lights and the slow one is faster it will most likely be the seal on the one that doesn't work. Mine did the same thing and by plugging one at a time it was easy to tell where the leak was.     Ray

I was having a similar problem. Started out by cutting the ends off of dry rotted hoses. Better Then the passenger side started to bind  - some white grease on the moving parts was a temporary fix, but it was obvious that 27 years of opening and closing had taken it's toll  , so..............

I went to the extremes, made the investment for piece of mind. All new hoses, filters and headlight hardware. Also a chance to pretty everything up. Have a look

 

It's actually not as intimidating as it looks! The most difficulty was encountered getting the units out without taking off the front bumper or the hood - got a few minor scrapes Getting ready for paint though. No biggie!!

On that note - I have 2 questions - does anyone know how to center the headlight doors - is it just the 5 mounting bolts? Also, whats the best way to aim the headlights - is there a base adjustment to start with?

Thanks

Paul

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