My fuel gauge indicates empty at all times.
The first suggestion I received was to replace the sending unit in the gas tank. I did that but the gauge still indicates empty.

I tried the HEC Dealer test mode and I now know that FUEL reads 255. Which should be an 'open' state.

The connector near the fuel tank does appear to be making good contact, so my suspicion is a broken wire somewhere between the rear of the truck and the front.
I tried following the wire on it's way towards the front of the truck, but I quickly loose sight of the wire as more branches enter into the wiring harness.

Where does this wire end? Does it terminate in the engine compartment, at the instrument cluster, somewhere else?

I just can't figure out how to narrow down where the break in the wire might be.

Is this the wrong path to take to isolate my fuel gauge problem?

Thanks,
Paul...

 

Paul,
Although never tried on newer cars, I always grounded the connection at the tank to isolate the problem. I would have someone watch the gauge (key on, of course), and use a jumper, from the disconnected wire to ground. Maybe jiggle the connector or scrape inside to be sure you have good continuity.
I'd expect the connector at the pump to fail long before any other wiring.