Sarah has to approve him before he can actually login. However, his new username appears right away. As far as I know, Sarah is home and should get to it in the next day or so.
To answer his question, the wires are already there for it, so I've been told. I'd like to know what year and model coach he has before I make a final conclusion, but there should be a wooden or aluminum box inside a cabinet that contains everything for the radio, including a power source. The only coach I had prewired was my 2251, which I never bothered installing a radio in it, but I know about the box. I had a sticker on a cabinet (between two cabinet doors) that said "Wires for Stereo or Speaker Here", and that was just outside of where that box was.
Again, if I knew a year and model, I could be able to point him to where that box would be.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR