Fuel Gauge

[BigMur]

2004 Tahoe Fuel Gauge just went from normal 10-2 o'clock reading to about a 5 o'clock reading. Is it an instrument panel cluster prob or a fuel sending unit prob?? Can anyone help??

 

[withac]

I know the stepper motors on them can go out and I also know sending units can go out, from what I'm told usually along with the pump itself. This is just me thinking out loud, but to me, I would think if the sending unit was going out the gauge would drop for lack of a signal or whatever, I wouldn't think it would force the needle way past the full point. I have no experience or first hand knowledge on this so I might be 180 degrees off but I would think stepper motor.

Anyone who actually knows what they're talking about care to chime in?