Gas Gauge 1966 F100

[Losvws]

Hi Everyone, My gas gauge doesn't work for my 66 F100. Common problem of course. I've gone through three fuel sender units already. I checked the wire that connects to the gas tank with my circuit tester and it wouldn't light up. Could it be a loose wire behind the instrument cluster? What's my next step?

[harrison28]

Before You tear into the gauges, I would trace out the wire that is supposed to supply power to the sending unit and see why there isn't any power getting back there.