Fuel Gauge Help
 

I took the boat out today for the first time in about a month and noticed that the gas gauge was not working. I figured it went out becuase it was old so i went out and bought a new one. But after i hooked the new one up it still didnt work. My switch for my bow lights control the lights on the gauges also, all other gauges work, as well as the bow light when i flip the switch. None of my gauge lights work though. When i hit the light switch my gas gauge goes from empty to all the way full and back to empty when turned off. Anyone have any ideas as to what can be causing this. My dad said it may be the fuel sender but just wanted yalls opinion before i bought a new one

make sure the sender is hooked up correctly and CHECK YOUR GROUND CONNECTIONS

What He Said! had same problem on my boat and it was loose ground wire at tank / sending unit.

Ok i have replaced the sending unit and the gas gauge but still not working properly. Now none of my gauges work and it wont allow me to start the motor. But if i connect a ground wire and a positive wire from my connection terminals then everything works fine except that while running the motor an alarm goes off the entire time, if i hit the trim switch it makes the alarm stop for a few seconds. On the other hand if i disconnect these two wiires then none of my gauges work. It seems to me like there may be a blown fuse in the ignition switch, is this even possible and if so where is the fuse located?

is there a fuse on the positive lead at the battery?
a breaker maybe to reset?