'97 Jimmy with Gas Gauge Issues

My '97 Jimmy has had an inaccurate gas gauge for several years now. Initially, it would read accurately until approximately 1/4 of the tank of fuel remained. After this point it would read full regardless of how much gas was in the tank. Over time this has progressed so the gauge only reads accurately until approximately 3/4 of the tank of fuel remains and most of the time the gauge reads full. I have simply been refilling every 200 miles during this time but I have forgotten a few times and been stranded so I would like to address it now. The gauge needle also oscillates in time with the turn signal when it is activated which may or may not be related. I am having no fuel supply issues so I don't think there is an issue with the fuel pump but I believe the pump and fuel sender are integrated in my model year so it may be necessary to replace it anyway. Any insight or guidance would be appreciated.

This sort of problem is pretty common in Blazers and Jimmys of that generation. I'm pretty sure it has something to do with the fuel level sending unit. Another thing about those vehicles and others built by GM is running out of fuel damages the fuel pump. Any time you run out of fuel it's like Russian roulette to your fuel pump, it could seize up any time.

Is it possible something other than the sending unit could be at fault or should I just go ahead and replace the pump and sending unit without trying to diagnose any further?

http://www.ebay.com/ Search 130762371837 Make sure you check the ground first.

You Have to check the connections at the harness, check for power AND ground......with the harness disconnected, should get a reading of full.....if you insert a 40 ohm resistor in the circuit, should read 1/2 full....if it does, need a fuel level sending unit.....

Otherwise you have to check the whole fuel level circuit, which includes a buffer module....

Sorry for the slow update. I replaced the fuel pump and sending unit (they are not available separately for my '97) and everything is back to normal. Thanks for the advice.