Headlamp Switch and Doors

The '68 Eldorado is unique in many ways.  Only the '67 and '68 had hidden headlamps.  The doors are vacuum actuated and rotate DOWN when the lights are turned on.  The '67 does not illuminate the parking lights when the headlights are turned on.  This is what the doors on a '67 look like in action.

The '68 leaves the parking lights on with the headlights.  This means the '68 headlight switch is not common with any other year, make or model car.  Damn.

Here is a picture of the headlight switch.  The knob is removed but mounts on the left side.  You can see the vacuum ports on top.  One of them is a vacuum feed from the engine.  When the switch is pushed in and off, vacuum is fed to one of the other two ports, pulling the headlamp doors up and closed.  When the switch is pulled out and on, vacuum is fed to the third port, pulling the doors down and open.

My headlight switch hisses when the switch is pulled out.  Hopefully the switch is not bad.  I'm praying for a cracked or loose vacuum line.  The doors still open and close, but a little slowly.  Also, there should be enough vacuum stored to cycle the doors two or three times after shutting off the engine.  Mine does not.

Also, my driver's side door is slightly misaligned.  It really bugs me.  Not sure what I'm going to do about that.

If I successfully install the Twilight Sentinel option, the headlamp switch is no longer used to port the vacuum to open and close the doors.  The switch stays in the off position and a photo sensor decides if it is dark enough to warrant the lights.  An amplifier takes the photo sensor signal and through a relay turns on the lights.  There is also an electropneumatic valve that takes a signal from the switch and ports the vacuum to the actuators to open or close the doors.