ok. rolling along...
There is a little button on the radio, right side low, between the 5 button and the band button. I can push it with a pen, and when I do I hear what sounds like the cd carriage moving. So some power is getting into the unit.
Front run bay, fuse 66 has 12 volts on each side, goes to F412 pin 4, purple wire. Disconnected connector verified the pin is ok, all looks good.
In the closet, 5 amp fuse labelled "dash radio switch (opt.)" hard to find a ground... popped the panel off, ground to the metal case of the water heater... Good. 12 volts on both sides of the fuse.
Time to go up front. Sure wish it was easier to directly post pics here... A smartphone app with direct from the camera uploads' everything in this would have a picture.