Gas gauge skip

[Cougar1Car]

What would cause my gas gauge on my 96 Yukon to fluctuate I can have a half tank and the gas gauge will go from half to empty and usually come to rest around empty.. Makes knowing how much gas in it a bit hard.. Thanks in advance.

 

[SunlitComet]

that effect is most often a worn out level sender in the tank.

 

[Cougar1Car]

That is what I was thinking...

 

[Gzes]

did it sit for a while? when mine sat for 7 or 8 years the gauge got stuck and after a good while it got unstuck but went loco going back and forth then eventually fixed itself.

 

[LI99HOE]

Could also be a bad gas gauge. Check the resistance coming from the sending unit in the tank before you drop and replace it.
On my '99 it's the two purple/brown wire plug just behind the gas tank by the bumper(not sure if yours is the same or not).
Also check the ground back there to make sure it's not corroded.

Search the threads on here..... It's been covered a few times.

http://www.tahoeyukonforum.com/forum/showthread.php?t=31053&highlight=gas+gauge ....
and there's more on here.

 

[letsbangout]

One word: corrosion. The sending units are notorious for developing corrosion because of sulphur in crap gas. GM's fuel system treatment was updated in the last 2 or 3 years to include an agent to treat corrosion on the sending unit. But chances are if the sending unit is responsible for whacky resistance values, to the point where it would bounce between half and empty, it's probably gone and no reasonable amount of GM fuel system treatment would resolve your problem. Definitely check it for resistance at the sender and then along the circuit to make sure.