Sorry if this gets lengthy but I can't find the same problem anywhere. I have a 67. When I purchased it had typical headlight problems aka vacuum motors bad. Also when when the high beams were swtched on headlight doors would close. I assumed the vacuum selenoid or high beam switch was bad. Did an electric probe door conversion now headlights don't go down with high beam switch they close after the headlights are on for a few minutes. They will open back up if lights are shut off and left off for a while. I checked voltage of red and yellow wire originally to the vacuum selenoid and now to the new relay for electric conversion and found no power when this occurs. It appears a loss of power to this wire causing the doors to close. It seems like something is getting hot and disconnecting and when cooling off it repowers. Is there a relay from the headlight switch to this wire or could it be the swich itself. Maybe with the old vacuum motors switching high beams was enough added draw to cut power as is happening now.