'75 Vacuum Headlights

Hi all, My headlights no longer go up and down with the light switch. They will go up and down however with the little switch under the steering column. I
have replaced all vacuum lines for the headlight system forward of the firewall. By blocking the right actuator and relay, the left side pops up and down like new. Likewise when I isolate the left actuator and relay. Operating together they won't pull the lights up or down, even tried squirting WD-40 in the relay ports like suggested here long ago. The only thing the light switch seems to do is get electricity to the lights. Any ideas on positively isolating the headlight switch as the culprit ? It looks like a bear to replace (standing on my head for several hours).
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I have the same issue on a 1978 corvette - Mine do not work at all -
W. Moore wrote:

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On Mon, 18 Sep 2006 20:13:08 GMT, "W. Moore"

================The Vac system on these cars has, and will be a problem.... However it is not difficult to solve IF one follows the excellent troubleshooting guide writen by Chris Prowl..and sold for 10 bucks or so by some of the Major Vendors... Its all of 2-3 pages..detailed and covers the wiper doors and headlight doors..
Chris gave it away a long time ago when he was active on the Vettnet and I understand he is still somewhat active on the C3 Registry (www.C3Vr.Com) ..
And yes I am plugging the C3 Registry ..why not, for 10 bucks a year you get (or can get) a heck of a lot of C3 help.. I got so much help I've been a Lifetime member for a few years...
Bob G. 64 72 & 98 Convertibles 76 & 79 Coupes
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