Gas Gauge replacement?

I was driving my CJ home today and it sputtered to a halt, out of gas, although the gauge was reading 3/4 full. Is this a common problem? Not sure if it's a gauge issue or a gas level sending unit issue.

Any ideas?

 

With the key on unplug your gauge wire from the sending unit, better to do this at the sending unit so you can check the wiring as well. If the gauge goes to zero ground the lead, if it goes to full tank it is most likely the sending unit. Anything else and you will need to check the wiring or the gauge. What year are we talking about?

 

It's a 78..and i'm a newbie. Thankfully my Chilton book came in last week so hopefully I won't have a hard time finding everything.

 

Ok good deal follow your wiring diagram in the Chiton, the sending unit will be on the top of the gas tank you should probably be able to reach it with out dropping the tank.

 

I really appreciate it. I'll let you know if i run into trouble. Thanks for the insight!