My son have an 88 Volvo 740. This past winter, when he went to visit his brother in Minneapolis, the car stalled out when he was traveling down the interstate. The diagnosis was a bad alternator and battery. Replaced alternator and battery and the car worked with no trouble for a few months.

This past summer, he didn't use the car very much. When he went to drive to school today (an hour drive or so), the car started fine but he noticed that the dash board lights were flickering and he called me while on the road to ask my opinion on what was happening.

When he got to school, as he pulled into the parking lot, the car stumbled and he had to goose the accelerator to keep it running. When he pulled into his parking spot, the car stalled out and would not start. The lights come on but when he turns the key to start, the lights go out but the engine does not turn over and the starter doesn't click.

I may have to drive over to give him a hand. Any thoughts on what might be wrong?

 

Your alternator is not charging.
Is the BAT light on on the dash when the key is in position 2? If not, that's your problem.
Measure the alternator output with a multimeter...

 

That is what I thought as well. He called AAA to see if the could help. They checked the battery and the alternator. Battery charge was low (as expected) and the alternator charging was low side of normal.

In the process they observed that the wire from the negative terminal to the frame was broken/melted. The larger wire to engine block was ok.

Could this be related?

 

definitely. a bad alternator ground wire interferes with charging, and can be erratic too.

my daughter's 87 240 did this recently. when I measured the voltage at the battery it was too low. when I measured the voltage form the engine block ground to the alternator B+ terminal (the fat red wire), it was low. when I measured the voltage from the B+ terminal to the alternator body, it was 13.9V. ahHAH! measured the voltage from the engine block ground to the alternator body and it was a couple volts. new ground cable after cleaning up the connections, voila, charges perfectly again.

not saying this is your problem, but it certainly could be!