From a post awhile back on here, my original part # on my old actuator was 1614822. Back at that time, when entering that part number into http://www.gmpartsdirect.com/
, it retruned a part called "Actatuor" but did not have a picture. I just tried it again and it returns nothing
Also, in some posts, there was some discussion that although the parts for the manual and automatic HVAC systems looked the same, they had different numbers and there was a difference in the "pins" in the electrical connector. Maybe you ended up with the incorrect one?
Here is a pretty good write-up about the pins and connectors