My headlight wipers sometimes do that, but move back in place next time I
use the screen wipers.

You don't say what car it is.

On the 9-3 they're only triggered by using the washers, possibly only
with the headlights on.

If you do that when they're free to move, they should park themselves.

Cheers,

Colin.

Try pulling the blades away from the headlight so they snap into
position pointing outward away from the car.  Then, run the washers for
several seconds (maybe with the headlights on depending on the model of
the car).  This insures that the blades will not run into the bumper or
stop should they be so out of position.  If your lucky when you snap
the blades down against the glass they will be in the normal resting
position.  If not, you can undo the nut thet holds the blade on the
splined shaft carefully tap off the blade and reset it to the normal
position.

"> I cleared the quite heavy ice from my front and back windscreen but
forgot

Check the fuse. Cant remember what number it is but it will be in your
manual. It is in the fuse box in the engine comparment.

Keith