car wont stay running and have to put a charge on it to restart. new alternator good battery and new radiator.

I would start with the basics if I were you. First check the battery voltage and check that the voltage stays at the same level and does not creepaway, next check all the battery leads, ensure that they are ALL connected and tight no corrosion etc, check that you have a decent earthing mountings to body and engine. Finally check with a meter that you have good charge rate amperage,voltage and amps leak. You may have a mega drain on the battery from a faulty consumer.

Definitely sounds electrical. Start by checking battery. Needs to be fully charged & without dead cells. If the voltage or amps are off in the battery your car could do strange things. If battery is good check your alternator next. If it's not putting out the correct voltage or amps (this sounds like your problem to me. Happened in my E350. Things slowly stop working, car goes dead) you car will shut down different parts as battery power dies down. If both battery & alternator are good then its computer or wiring problems and that's bad. 99% chances are its alternator or battery