I have had the same problem on my 306 if left they will completly break down, mine lasted about 18 Months before I threw in the towel, I spoke to my local mechanic and he said "it is a common problem and normally the motor at fault" which proved to be true after replacing the motor (Peugeot price for a new one £187.00) but I sorced one on E-Bay for £40.00 and it works perfectly.
peter field
December 2009