1985 W150, 4x4 360 Truck. Truck will start and run for about 2 seconds then die.,,,, Plenty of gas and fire. Plugs, wires, cap, rotor, voltage reg, ignition module, coil, resistor all néw. I swapped out coil, cap, starter relay, ignition module, and resistor just to see if they might be faulty. My final attempt I ran a hot wire from the +coil to the +battery, starts fine, runs fine. Best research I’ve found was that it’s a relay switch. Any opinions or suggestions?