1993 honda accord Fuel Gauge not working properly sometimes it shows fuel when i am driving fuel gauge is going down now the fuel gauge shows pass empty. Can it be fuel sending unit Or Instrument Cluster that is bad?

 

It could be either?

You would need to get a volt meter and do some testing at the sending unit as a start....there is a "panel" in the trunk (right/pass side) where you can get to the top of the sending unit to do some testing there.