Volvo: stalling volvo not alternator, random times, fuel pump

Question
Help!!!!!!!!!!  We have a 1989 DL volvo sedan 225,000 miles.  The problem is it keeps stalling. Mechanic keeps saying must be the alternator,despite installing three alternators in a row, new starter, new battery and new distributor stalling remains a problem when stalled it wont even turn over, it will start with a jump and stalling is at random times.

Answer
Paula,
Stalling and will not turn over sound like two separate problems. Stalling will have to be diagnosed when it happens. Things like fuel pump and pressure will need to be tested, see if the car has spark. Now if the engine will not crank (turn over) then that has to be tested at the time also. Is there 12 volts to the starter on the large wire? When the key is in the crank position is there 12 volts at the small wire? There may be enough voltage at the starter large wire, but not 12v at the small wire at crank.
I would seek out a shop that works on Volvo's regularly and let them look at the car. The shops that work on the cars daily have more fault tracing experience.