Hey everyone!
So I've been having problems with the headlights on my car ever since I got it. It use to be that the passenger headlight would be normal and the driver side would be very slow at the beginning and then it would go up. Recently it got so bad that the headlights didn't go up at all. I got a rebuild kit for the seal on the driver side headlight actuator and it helped. It brought the car back to the condition that it was in before where both headlights went up but the driver side one was still a bit lazy. So then I did the test on the RELAYS and found that both were bad. (I plugged in a vacuum pump to the center hole and close off the bottom hole, I later confirmed they were bad by doing this same test to new ones I bought, the new ones held pressure). So I replaced both of the old relays and It actually ended up making the problem worse. Now only the right (passenger side) goes up. I am completely lost, here are some other tests I've run with a vacuum gauge that can also read pressure to help narrow down the problem. Additionally, when the car shuts off I hear a loud hissing from the right (passenger side, the one that's working).

Switched all vacuum lines on both relays to check if one of the new relays was bad, same result right went up left did not.
Put the vacuum psi tester to the hole on the relay that sucks vacuum in to bring the respective lights up, on the right side (non working) there was 15 psi of pressure on the left side there was only 7 psi of pressure.

I am totally lost looking for all the help I can get, thankyou in advance!

 

I'm learning about headlight vacuum as we speak. Willcox Corvette has some good videos and colored vacuum diagrams that I am using.
Is the small black bypass switch under the driver's dash pushed up all the way? If it is pulled down to the bypass position it will make testing the system impossible.
Also...repair all vacuum leaks before doing any teting in order to get accurate results.
Let us know if the Willcox videos help you find the problem.