I drive 15 miles to work - highway speeds - and when I pull up to a stoplight the Ranger just quits running. When I try to start it, it turns over slow like the battery is dead. If I wait a minute or two, it starts fine. The local mechanic changed the battery and cable ends. The alternator is testing fine.
If it has an automatic transmission, the lockup torque converter may not be releasing at slow speeds. Next time, as you approach a stop, put the transmission in neutral. Results?