I am new here to the forum but I wanted to share what I discovered today in the hope that it might be of use to someone. Y'all might already be on top of this one but anyway - here goes.....

Headlights working very poorly on a 76 model - i changed out the actuators because one of them had rusted thru on the underside, put new lines from start to finish and still wouldnt work properly - one would pop up after a few minutes followed by the other one a few minutes later. So i decided to change out the relays - got a slight improvement, but I am looking for "straight off the production line" performance, not this snail speed crap.

Come to find out that the inlet to the vacuum tank was 99% stopped up (it did trick me at first because when you pull the outlet line off a bunch of air sucked in to the tank leading me to believe it was getting enough vacuum - not so). Also, I pulled the vacuum port off the headlight switch only to find that it was pretty clogged as well.

NOW - it is like my headlights are in a race to see which one can pop up first - I dont think they worked this good back in 1976! Going down - the same - and so quick they look like they shut (and open) together. Yes - life is good, tonight! Now - if I can get the rest of the car to run half as good I will be a happy camper.

Hope this helps someone out.

Cheers,
Brett.

p.s. to work the headlight system and to check the A/C actuators (i had the whole car gutted out) I plugged my A/C vacuum pump into the main line coming off the intake - it doesnt suck like the engine does so you have to let the inHg build up, but then it works everything vacuum operated without having to run the engine!

 

Yep. Good work. I have found the inlets to the relays to both be clogged on more than just my own Vette.