I have a 96 Ram 1500 5.2l, I have replace ECM, Coil, Distributor, Crank sensor, and ignition switch. It will run about a hour then shuts down, and won't restart until it sits awhile. Then it will restart and run about a hour. I discovered if I replace then ASD relay it will restart and run for about a hour. Can anyone give idea where to begin to look to what is causing the relay to shut down?

 

When it won't start need to see what is missing fuel or spark. If you didn't use Mopar sensors that could be your problem.

 

Missing spark, when I replaced relay starts right up

 

When something stops working and recovers after a while it's often a temperature related issue. Does the relay or one of its pins feel warm when the problem occurs ? Can you reuse a previously removed relay after an hour or so ?

 

The whole relay is hot, yes most of time I can reuse the relay after it cools.

 

Check all connections for the relay, at both ends. I suspect a poor ground, causing it to heat up.