So a long while back I had a side project to install a stereo from an 04 Sunfire (it's the same stereo that's in the Montana) in my 03 Grand Prix GT. I have most of the wires figured out thanks to the Montana and Grand Prix diagrams in Crutchfield's knowledge base. The issue is that the new stereo doesn't have a traditional switched power (accessory), but instead turns on via the data line in pin #1. Can I just wire the ACC wire from the 03 GP side of the harness to the data line on the Sunfire side of the harness to get switched power?
*EDIT*
HERE is the diagram for the 04 Grand Prix (which uses the same harness as the Montana) and it seems to be more intuitive, but I still run into the switched power issue.
