1984 400i 22,000 miles, always garaged. Yesterday, I changed the oil after the car has been sitting for a little too long. Went for a drive and everything was great. When I got back to the garage, I noticed that both headlights were "up" about 1/4 inch. When I start turning the knob on top of each motor, they suddenly open full under their own power with no headlight on and then fully close themselves. They do not cycle repeatedly. Lights were working perfectly the last time I was driving at night, but I don't really know how long ago that was. The car has not been washed. The light control stalk feels right. I find no fault with fuses or relays. What an I looking for? Any help appreciated. Tony
Check for moisture in the 4 pins connector that is hidden in the left fender (close the the lifting motor). Do the same with the other connector on the right fender. Check for mechanical failure: if you disconnect both connectors, you can manually operate the lifting motors. There is a knob on top of the rubber boot that protects the electric motor. This knob is roughly the size of a coin. You can turn the two knob until both headlights are up. The headlights are heavy, so this tasks requires a bit of force, but excessive force would mean there is a mechanical failure. If the gears of the motors are not damaged, you may have to open the mechanisms and check for electrical gremlins : two mechanical switches and two diodes are used to reverse operation and send feedback to the dashboard. Some users on this forum have had diode failures.
FIXED IT! I followed the instructions in the 308 section on repairing the control stalk https://www.ferrarichat.com/forum/threads/instructions-for-fixing-a-headlight-switch.257534/ 10 minutes done.