Wellcraft Boat Owners Forum

Upgrading the points ignition on my 89 Mercruiser 181 cid to the EST pointless ignition. The EST distributor has two plugs, one from the coil and the other from the module, has 4 pins. The setup I got had the coil to distributor harness, but did not have the harness for the 4 pin male plug that goes to the HEI module. I got a standard 4 pin female harness. What I know is that in run mode, this plug only uses one wire/pin. In timing mode, it uses 3 wire/pins. The problem I'm having is which ones in each mode. The first diagram just shows how the pins/wires are labeled. I searched the internet and ultimately came up with a series of diagrams that seem to contradict one another. In the second diagram nothing is labeled, but the position of the wires makes it appear that in run mode the single wire used goes from module pin R to the shift interrupter. In timing mode, pin R is instead connected to a 12v source and the jumpered wires are pins G and B. The latter seems logical because in timing mode, the advance function is disabled by grounding via pin G. However the third diagram shows the wiring in reverse: in timing mode the jumpered wires are R and E, and the 12v source is B. In run mode, B would apparently be the wire to the shift interrupter [which happens to be white/green]. The fourth picture is of the EST distributor in timing mode and shows the jumpered wires in what would be the R & E location.
If any one can clarify this for me, I would be eternally, well at least grateful for life.