1984 Ram Crank No Start

Mattax said
by '84 Chrysler had changed to ECU's that no longer required the 5th pin

It seems odd the harness has 4 wires, the plug 5 female connectors, and the ECU 5 pins.
Does that mean a 4 pin ECU will work as well?

Mattax said
What wire did you touch to ground?

I disconnected the 2 wire connector from the harness to the distributor, each end has a long pin on one side.
Key in run, I touched the long pin from the harness to ground and the coil wire would spark.