MY 91 VOLVO 940 HAS BEEN DYING LATELY AND WON'T RESTART. IF YOU JUMP IT, IT RESTARTS, BUT THEN SPUTTERS AND STALLS WITHIN ABOUT A MINUTE. BEFORE IT STALLS, THE SPEEDOMETER BOUNCES UP TO ABOUT 20 MPH EVEN AS YOUR SITTING STILL. THE MECHANIC REPLACED THE ALTERNATOR AND I TOOK IT BACK IN AND HE SEZ IT ...