Mondial 3.2 diagnostic port

Reinstalling the engine into my 1988 Mondial 3.2 cab and can't seem to figure out where the diagnostic port wiring goes. I know it mounts on the valve cover but where do the three ground wires go?

 

Does anyone know where the relay for the oil cooler fan leads to. I have three wires and it appears an aftermarket relay. One goes to the fan obviously. The other to a power source. I thought this was the starter power cable but a diagram appears to show it goes to the ignition coil and the third I assume goes to some sort of sensor on the block to signal that the oil needs to be cooled via the fan. Any ideas?