Car dies after starting

Several times over the last few weeks my car has died shortly after starting. Tonight it started to do that on the way home. My son-in-law said to check the relays and fuses. I know how to check a fuse, how does one check a relay to see if it is good or not?

This problem is not likely due to a relay or fuse. It might help to know the year of the car, engine type, and mileage.

Checking for codes would be a start.

If you’re saying the car died at speed, not just at idle or after startup, then it could be any one of a 100 things. There’s simply not enough info known to make much of a guess.

The year is somewhat important because early and later models could have vastly different causes for the same symptom.