Ignition Coil Overheating

I have another question. I dropped in a new Billet distributor and the wire connection was different than what I have. The distributor instructions identifies the leads to the ECU as Positive and Negative which is fine. My problem is there connection to the ECU. I looked at several wiring diagrams which show the leads from the distributor to the ECU but none late whether Pin 4 on the ECU is Positive or Negative.

Does any one out there know whether Pin 4 on the ECU is positive or negative?