Try this. Different year, but close wiring set-up.
http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=61555
Looks like your Pin #2 is the problem. From what you described, with ign. on you should get the 12V with a probe on #2 pin on the car side, and the other probe to chasis ground. This should go through the connector to the starter. You're getting -0- Volts. Athough the starter actually should be on Pin #1, typically Yellow.
Hard wire Ground connections are Brown and there is no need for a ground through the 14 pin connector. That's what the braided chasis straps are for and why they are very important.
You'll drive yourself nuts on the voltage for the pins as some are not live until the enging is actually running i.e. the sensors and stuff. And some are only acitive during the starting cycle. And some are not even connected to anything on the engine. Plus you will get no readings from the Alternator connections (charging circuit) back to the battery while the connector is disconnected as another example.
Your ???s after the pin #s are because those pins are only used if you have certain equipment like Tip-tronic stuff as an example. Typically, 2-7-8-12 are not used- on the engine side but are indeed there on chasis side.
This info is for my '77 so take it with a grain of salt.