I need help with gauges

[The Weasel]

So I am getting ready to buy new gauges to put in my truck but I still have not found out about the fuel level sending unit. The stock one in the 84 stopped working correctly years ago. I don't know if it is the gauge or the sending unit or a bad connection or what. I need to know what the resistance should be on the sending unit so I will know which gauge to buy. If the gauge doesn't fix the problem then I will try to get a new sending unit.

 

[originalnitro]

Ford sending unit are 10-70 ohm. You can check the gauge by unplugging the sending unit from the top of the tank. Gauge should read full when unplugged. If it reads full check the sending unit it could be something as simple as a hole in the float which is a cheap fix.