My gauge doesn't work at all and I think it's because of a bad floater on the assembly. If I buy a whole be assembly if a new pump and filter and everything will it work?

 

You need to find out first if your gauge works without the assembly. You just checking for resistance an easy way to do it would be a old tps three wire and then make your own leads and hook them up to the connector where the you would hook up the pump. Have someone move the tps sensor arm and see if the gauge does anything. If not your goin to have to trace the wires back to the cluster or even wire in your own gauge.