instrument cluster wiring

[Tractor or wife]

I have 73 ford 3000 diesel that i have just replaced the wiring harness and instrument cluster. When i got the tractor most of the wires were melted beyond recognition and there was no gauges. I am haveing issues trying to wire up the cluster. I only have 3 wires blue black and white and i am not sure where they go or which bulb wire goes where. I have only been able to find one pic online that helps a little but the back of the cluster is different and so are wire colors
I think the blue wire is oil pressure sending unit because that is the only blue wire that i have in the harness but i still am not sure where it plugs into the cluster. I also think the yellow/black bulbs wires might be illuminating bulbs for the whole cluster but i am not sure. I called a buddy and he said i was missing wires but talking to the company i bought the harness from all wires all there.

I have been reading tractorbynet for 2 years and have seen this issue before but cannot find thread. Please help.

 

[JD40MO77]

I have a 1973 Ford 4000 diesel and in process of trying to source a wiring harness also.......possibly https://www.tractorpartsasap.com/Wiring-Harness-For-Ford-Tractors-p/113582.htm this one says it fits Fits Ford 2000, 3000, 4000 .Replaces C9NN14A103B, C5NN14N104R.
Just wondered how this compares to the one you installed and how your tractor turned out....... I installed a new cluster 2 years ago when I 1st got the tractor and didn't consider swapping to a alternator from the generator....