Hi Richard, The bose repair guy is Dr. Don's.com. I believe they are in Texas, but I'm not sure. They can do wonders with the system. Also there is a web site called Factorycarsterorepair.com. They have a decent troubleshooting section & they are very cordial on the phone.
I'm no expert on the tranny swap, too new of an owner. I know people have done that swap. I'll bet Jeffvette knows what's up with that or maybe call Mr. Haibeck or zfdoc.com, Mr Bill Bourdreau? Sorry I'm not much help on the tranny!
Good luck,
Tom
On the fuse thing. Do you have the electrical book in your service manual set? I would think that the radio & the A/C must have either a ground or a source(power) ckt in common if both go out together? I have a wiring manual with my Helm set for my 1990 Z. Give me a shout & I'll look it up and see what's up.