Fuel Sending Unit Question

[jamieaburch]

Just replaced fuel tank on my 79 and now fuel gauge reads empty. Is this a ground problem? The gauge was working before tank replacement. 

[hatzie]

The sender wire is shorted to ground or the sender has failed.

[jamieaburch]

When you say sender wire is that the power wire?

[ehjorten]

There is a ground wire that goes to the top flange of the frame rail for the sender.  Did that get connected when you replaced the fuel tank?

[jamieaburch]

I had to splice it back together and now I'm thinking it may have come loose when I put tank back in. Can I ground the wire to the frame or does it have to ground to the tank

[bd]

An open ground will cause the fuel gauge needle to swing past full to about 3:00 o'clock.  As hatzie stated, for the gauge to register Empty, the signal lead is effectively grounded (either directly or through a faulty sending unit).  @Jamieaburch, the signal lead isn't actually a power lead, although it does have measurable voltage on it.  Make sure that you didn't accidentally splice the signal lead to ground.

[jamieaburch]

Thanks bd. I will check when I get home