Hi,
Just an update. I found this description and circuit diagram of a two speed wiper circuit which proved invaluable:
http://www.netlink.net/mp/volks/schem/wiper.htm.The short is actually in the motor itself and is there to slow the motor quickly into the parking position. This helps it hit the same parking spot each time. I now need to make sure the Park link to earth is opened before by switch applies power to the motor. So I will try a two pole make before break changeover switch .
Thanks again for the comments.
David
