There have been several posts about using the park switch in the Valeo 15094704 wiper motor (sold by All Electronics but currently out of stock) on the haunt forums lately. Below is the document that is included with the motor from All Electronics.
One source identifies this as the motor used in several 2002-05 GM SUVs.
I don't have any of these motors but located a wiper schematic for a 2002 Envoy and thought they might be helpful if the cross-reference is accurate.
This is a diagram of the wiper motor:
This diagram shows the wiper control switch. It is interesting that the intermittent function is just a matter of varying resistance.
And here is the face of the connector that plugs into the wiper motor. Note that this would be the mirror of the motor pins as they are pictured on the sheet above that comes from All Electronics.