Gas gauge needle movement: normal or excessive?

[LuckyLightning]

Hey all,

I just wanted to check to see if my gas gauge needle is moving like it should, or is it moving too much.

Video here:
https://www.youtube.com/watch?v=kpnb18IisTY

If it is moving too much, any ideas on cause and solution?

Thanks.

[Alex41]

With all the things you pointed out going wrong all at once in the vid, it looks like you have a serious ground issue.

The fuel gauge on mine did the same thing till I tightened the ground that goes to the top of the fuel tank hat to the frame better.

The rest of the stuff going haywire like that makes me think the ground behind the dash near the drivers ac vent may be loose.

[motornut]

All the grounds go down to one about a foot behind the cluster plug.
my 78k did that
https://www.youtube.com/watch?v=e-8a7m5UCXo
and it stopped when I changed the cluster from idiot to Tach/gauges.
But I had to add a "new" ground just for the gas gauge.
some say it's the float or gauge,to change it.
my 79c didn't do it before I changed the tank/float or after using a Spectra tank/float
and yes,confirm the ground is clean n tight over the Ebrake

[LuckyLightning]

I found the ground issue: wire coming off the fuel sending unit seems to have a weak connection. It's very difficult to get to, so I may have to wait until I have time to remove the bed to get to it.

Also, I'll check the grounds behind the dash cluster soon - thanks for the tip.

[Chaplain]

Good info. I'll have to check that too.