gas gauge bouncing

can anyone help me out? the gas gauge neddle on my '48 chevy p/u constantly bounces. it reads gas in the tank but bounces between full and the level it should stay at. how can i fix this problem? please help.
<!-- / message -->

 

Why two threads on this????

 

????????

 

just screwed.

 

just screwed up

 

I had this problem with an aftermarket sender. It was the float arm losing ground as I moved up and down. I attached a wire from the arm to the mounting bracket. This fixed my problem.

 

inside the tank?

 

I have the same problem, Sombody said the arm is too long and not reading right.

 

no. its electrical. it bounced even standing still.

 

loose ground?

 

I'd go with a bad ground as well, an easy place to start and may wind up costing you nothing to fix.

Bob

 

I had the same, was a loose wire.