I belive with that Relay your talking about, the engine should turn over, but not Run, I had a similer problem after I just got my Trooper similer to what your talking about, It just stopped running. First we check the Fuel pump and yes we had to drop the tank with full fuel....., It was WAY to small of a pump and wasnt keeping up and We think It was Vapor Locking. We got the Pump that was the right one and It was much bigger in diameter. Took care of that problem, If you have to drop the tank and it not the pump check that Filter thats on there for junk. Still it wouldnt run, checked that relay along with all of them and replaced them and Bingo, It ran, much better. and it didnt stop running going down the interstate. That relay maybe your problem. I would check that out and Im sure if its melted something is wrong with it.