No power to ACC fuse and no cranking
 

Installed a AVIC D3, operated it fine before mounting after I'd done all the wiring, and had to leave town for a few days so I left it sitting still hooked up but not installed. Came home - doen't play and car won't start. Panel lights up but no crank at all. Battery is fine. ACC fuse blown. Replaced but still no crank, and no power to acc socket either. Using a DMM I find no 12VDC at the acc socket with the fuse removed. Like something big popped and even though it blew the fuse it took out something else? Would this stop the car from cranking? Seems mosre like some immobilizer feature, like maybe my key programming got erased or something. Even changed the ignition switch but no change in problem. Help?

Bad ignition switch is a possibility, could also be one of the high amperage fuses (aka Fusible Links), F4 - Ignition lock is one possibility. They're located under the dash in the passenger seat footwell under a sealed cover. Read lft to rht F1-F7. Pull F4 and test for continuity with your DMM.

Did you try to jump start the car? If that works then your Power wiring for the D3 is backwards.