HEDALIGHT Disperate faulty, Unexpected fault Options

[searunner]

yesterday coming into my garage, I hear one ritming song- under the cover of my 914 2.0 1974, one strange movement, the LEFT Headlamp go UP and DOWN
The RIGHT Headlamp stays in the closed position.
Normally, I detach the battery of the car when in the garage, but I forgot this time.
The car was without a KEY IN - the Light switch was off -
The last trip with the car ALL was regular, and the headlamp was in working condition.

I can STOP the movement, detaching the battery- but this NO was the solution,
Then I searched for a better solution.
Extract completely the Light switch -(with the BATTERY connected and KEY ON) I have the two headlamps is up and in stable condition - also when I START the engine and move the car, and make a long trip

But if I return the light switch to the POSITION light, the LEFT Headlight return to UP_DOWN movement.

Is clear that I have one short- Or one Relay issue - BUT 914 was full of relays
Can someone help me, to return to a normal 914 ??
I am not a native English so overlook my errors