So as I posted recently I just purchased my long lost love, a 69 RS.
I bought the car knowing full well the plumbing was there for the hidden light covers but the former owner told me they were not working.

So deciding this was the first thing I was going to tackle, immediate I found a major part of the problem. The vacuum line running out of the carb and around the back of the engine was completely disconnected. Had a bolt in the end of the line. I hooked that back up, tuned on the headlights and the doors opened! Considering Im not a engineering genius I considered that a major victory.
Tuned the lights back off and the doors won't close under vacuum. I manually pushed the doors shut and then tried the same from the vacuum relay. Same result, they will open but not close.

It seems like the doors open and close smoothly. No binding. Just under pressure when I try to close them.

Any suggestions as where to look next?

Should I vacuum test each line individually or could it be the acutators?

 

Are the vacuum relays there too, or did someone "hotwire" the vacuum directly into the actuators? If relays are still hooked up, switch the two hoses going to the headlight doors. Now open would be closed and closed would be open. If the doors now close but won't open, the relays are bad.

 

I should have said only one relay, not relays. I'm used to my 69 Vette, which has two. Here's a vacuum diagram and troubleshooting directions: Technical Reference Series II #001

 

My vacuum relay is there. I can toggle the plunger and get them to open.
That link you sent is the one I've been working from and the diagram on it matches up to exactly what I have. Whoever took the time to write that up is a god. I had no idea how it even worked until I found that gem. At least that gave me a basic understanding of where to start.
I'll try to flip the hoses. That sounds like a good idea. Its only 93 degrees outside right now in the shade so I might wait until we have a cool off then try it. It will give me something to think about in the meantime.
Thanks again and I'll let you know as soon as I find out something.

 

To know whether your actuator is the culprit, bypass the relay by directly connecting the supply vacuum hose to the hoses to the actuator, one at a time of course. If the actuator is dead, take a look at the rubber boots that connect to the actuator rod and the can. If that is ripped/cracked/missing, then the actuator won't work in one direction (can't remember which way). At least, I found out years ago that's how the Vette works, or doesn't, and your vacuum stuff looks a lot like mine.

 

I'm all over it like stink on poop. As soon as I run those tests I will be back here with a result.

 

Also make sure your hose connections are snug. If not, cut off the bad end and put back on. A loose one here, a cracked one there, can add up to a big vacuum loss and sluggish lights.

 

And to help troubleshoot the vacuum system, you can use an air tank and a rough vacuum pump - A/C evac pump - to use as a vacuum source rather than burning $3-$4 gal gas.

 

Good idea about using a vacuum pump, especially if wanting to work in an enclosed garage without committing suicide.
His car has a vacuum tank though. It would make more sense to me to just connect the pump to the intake manifold vac hose.

 

Yea guys I do. My father has a hand vacuum pump that I'm borrowing for this. It's only gonna be 105 in the shade today. I may have to get out there and do it anyways.