Irratic Fuel gauge and trim gauge pinned

[atrinh15]

Hi im new to the site. I recently purchased a 2002 Hurrican Fundeck 188 with a Yamaha 100HP 4 stroke. The gas gauge jumps from E to F and sometimes stays at F.

My trim gauge is not working at all. Just pinned UP all the wires are connected not sure where I should start. Please any help and pics or diagrams would be appreciated

Thanks
atrinh15

[boats.net]

Would need to test for 12 volts between purple and black or if has Yamaha gauges then Yellow and black wires at gauges with ignition key on. Test fuel sender at gas tank and trim sender on engine.