Possibly Overheating?

Hi all. I hope someone could maybe give some advice regarding my motor.

I have problems with my temp gauge reading off the scale permenantly! Even with driving only 2 or 3 miles.

I had to rewire my vehicle as it was a bare shell when I got it and there was no trace of wire anywhere in it.

I have got all the electrics sorted but I am very worried about the temp gauge.

I have the original temprature gauge for the car and what is supposed to be the correct temp sender unit for it. I am told however that on theses earlier vehicles that the circuits would have been operating at a lower voltage than the normal 12v.

As I have made my own loom there is NO resistance fitted. I have taken power from the ign switcg to the gauge and then from the gauge down to the sender unit.

I have also been told that later fords such as escorts / granadas / cortinas / capri were all 12v systems. Could I just chane my sender unit for one of these others OR would it stillread wrong as it would not be for my type of engine?

Just one more point to make which is these engines do run VERY hot anyway but surley if it were that hot it would have boiled over and probably seized up which it has not. I did remove the fan bolted to the front of the engine and fitted twin electric fans with a low grade sensor and the fans are not cutting in. I have tested the sensor and the fans and all is good. To aid in the cooling of the engine I also have an oil cooler fitted.

I have tonight removed the thermostat although do not suspect it to be faulty besides I had drilled 2 holes in either side to aid water flow and stop any air build up in the system.

Anyone else have similar problems or able to suggest what my next move should be?

Thanks in advance.

Dr G