Volvo Repair: Faulty headlamp wiper/washers on a 99 Volvo XC70 wagon, volvo xc70, windshield wiper

Question
I own a 99 Volvo XC70 cross country wagon. When the headlamp
wiper/washer is activated, the wiper arms move from park
position to about a 6 o'clock position on the headlamps and
remain in that position. They do not return to park position. If I
wait a while (2 hours/more), and then start the engine, the wiper
arms will return to their park position. If/when the wiper/washer
switch is activated again, the same problem repeats itself. The regular
windshield wiper/washer system works fine.

What do you think is causing this problem and what is your
suggested remedy?

Thank you for your time and assistance  

Answer
I have been thinking about this problem for the past few days.  It is very unusal for one to break like that.  Usually they both just stop working.  I suspect that it is the computer giving the problem but really with these unusal symptoms I'm not feeling very confident with out inspecting the vehicle myself.  My suggestion would be to take it to the dealer and pay the diagnosis fee to get a firm idea of whats going on.  Usually they charge 1 hour of whatever their flat rate fee is.
At that point I could give you help in installing whatever part they say is defective.  If it is a computer though, they will need to program so let them do the work if that is the case.  I hope that helps.

James