Fuel gauge wont work on 7.3 diesel. is there a way to test it ?

Somewhere like AutoZone will loan you a fuel rail pressure gauge. Somewhere on it there is a test port. You screw it on, and test in two ways. 1. pressure with the key turned on. 2. Pressure turning over. Compare against specs.

Opel Corsa bakkie 1.7 dti , NO YEAR TOLD! WOW HARD. in AFRICA?
fuel tank empty
OR gauge fuel lies.
or level sensor bad and lies.
some cars if oil pressure is dead it cuts fuel.
fuel is bad and or is water soaked,
fuel filterS bad.
fuel injector pump BAD (No year impossible answer)
FUEL PUMP BAD, OR NOT PRIMED.
GLOW PLUGS DEAD.
yes i can be any of that'
and more,
does spray test fuel work to engine intake? by hand.? work? (short time)?
check all fuses first so glow plugs work?
engine compression ok if test fuel test fails?

Could be the gauge in the instrument cluster ! There are videos on youtube on testing fuel gauge .
Repairing Fuel Gauge Problems 2004 Mercury Marquis EricTheCarGuy

How to test fuel gauge tank sending unit P0463 GM

You don't say what make , model an year vehicle . Testing before replacing parts is the way to a proper fix .

The function of diesel fuel system is to deliver the diesel fuel to the engine clean of of purities at the right pressure. In most generating unit diesel engines, the fuel system loop consists of the following major parts:
1. Day Fuel Tank
2. Fuel Water Separator
3. Fuel Strainer
4. Fuel Supply Pump
5. Fuel Filter
6. Fuel Injection Pump
7. Injectors
8. Return line to the day tank
Hope it can help you.
Maybe You Also Like: http://www.dieselgeneratortech.com/diesel-engines/basic-working-principle-of-diesel-engine-fuel-filter.html
http://www.dieselgeneratortech.com

On the WEB
images for gmc sierra 3500 diesel fuel gauge

Hi , there will be 3/4 wires at the fuel tank gauge. 1 ground wire ,1 gauge(on dash) wire, 1 gauge low level indicator light (warning on dash) Get a test lamp , ground test lamp and probe each wire. 1 will do nothing (earth wire) 1 will bring on dash low fuel light , the other will be the gauge on the dash which will rise (slowly) to the full position.

The gauge gets it's "juice" from the sending unit which is located in the fuel tank.

Normally, only 2 things stop a diesel from firing:
1. no fuel
2. not enough compression

No fuel can be caused by (obviously no fuel) or a failed fuel pump. To test, have someone turn the engine over and then sniff at the exhaust - does it smell of unburned diesel? (If you've run out of diesel recently, you may have an airlock in the system, this needs bleeding out.)

Not enough compression needs specialised equipment to test - that's a garage job.

no that would not cause a smog failure

NO year? post year, and win.
what country.> stated, why?
cranks ok?
diesel test fuel work>?(spray test)
filters fresh.
fuses ok
scan it yet?
glow plug tests fail>(ask or read the SM?)