M30 Blower Motor Resistor Connector Problem

[JanM30Al]

I just received a replacement Blower Motor Resistor assembly and it has an electrical connector with 5 contact blades. Problem is, the original part has a 3 contact blade connector. In checking all the various sources on the internet, it appears that the replacement part from all suppliers has a connector with 5 contact blades.
Examples at these links:
http://www.rockauto.com/catalog/moreinfo.php?pk=1188388 ,

http://www.rockauto.com/catalog/moreinfo.php?pk=1312725,

http://www00.mailcar.net/catalog/index. ... GoogleBase

Anyway, it looks like I'm going to have to make a non-plug-compatible part work. How can I determine which contacts to use if I have to cut the harness connector off and solder wires directly to the connector or the blower motor resistor assembly?