2000 s80 car will not start

[redled123]

Car showed notice on message board , Anti-lock brake failure. Car had lost power, A/C compressor had cut off, remote keys would not work. Towed to dealer, they replaced alternator, said that the old alternator was not putting out enough amperage.

Car ran fine for two weeks, same thing all over again.
Starter turns over very well, plenty of juice in the battery. I cannot understand the relationship between the problems stated above and the lack of remote key operation.

Another Mechanic tells me that the computers are not communicating with each other (not a regular Volvo Guy)

Come on guys, need some help with this, just about at the end of my rope, hate to have to junk a really beautiful car..thanks in advance for your help