While driving my 95 850 turbo, the radio goes blank, then the dashboard lights come on and the car stalls. This has occurred three times today. Any idea as the issue?

 

sounds like a connector may be loose or you are having alternator/voltage regulator issues. Does the car reset right away after the stall?

 

The car drives well. I just have to disconnect the battery after each use as I don't know when the lights may come on the dash and run down my battery

 

Speaking of the battery? How old is it? Generally I live with the idea of replacing batteries every 4 to 5 years now, rather than waiting for the inevitable. I've noticed Volvos are more sensitive to this than others. If your battery is over 5 years old, that would be my next step before proceeding further. IMO. Good luck. I've seen way to many Volvos that start just fine, and then the wife goes to the mall, and then to the market, and then with the 3rd or 4th start in under a half hour the battery just can't deliver and what you describe ensues,....