1997 Nissan pickup ka24 engines motor dies when hot but will restart?

Try the wiring harness its a long shot but they dont last forever grab the wiring harness where it crosses to the engine from the body and give it a good yank around while the car is running if ti stops then it can be a broken wire in the harness.

Also try interigating the ECU for the Fault code that should give you a good idea where to start