Outer Limits 4x4 Board

Hello there , Could someone please help me with the connection from a 1979 HJ45 wiring loom in the engine bay to connect to a standard wiring on an 83 2H, it is the edic wiring , which the 75 plugs are square and the 83 2H are round, I have the complete 83 wagon with its original wiring available also. My w/shop manual is next to useless in this regard. Look forward to getting this sorted.
Cheers,
Bob

My hj45 (conversion done by previous owner) with a 2h has a manual shut off (adapted cable) to stop engine. EDICs are a weak spot in my experience with 2h motors.
Hope this helps
Griffo