dssur
+1y
You have blown the constant 12v fuse or shorted that wire in the harness. The symptoms you describe with the factory radio, just static and no display, that is the exact cause. That also explains why your new one doesnt work.
If you put a test light on the yellow wire of the pioneer, you should have power even with the key off. I promise you that it is not on. DO NOT PUT IN A LARGER FUSE SIZE. Most likely you were jacking around with the harness before you soLDERED all the wires together and the yellow wire touched the black wire or the steel of the dash. Thats all it takes to snap a fuse.
Check the fusebox. Thats your problem gauranteed. I installed for 10 years, every time a factory GM (Saturn is GM) radio was static and no display, the 12v constant fuse was out.