Fuel guage wiring question

Hi,

I have a problem with the fuel guage on my boat, it hasn't worked since I bought it a month ago, and I've hit a brick wall now. The guage reads fuller than full when the ignition is on or off, the sender might be shot but I'm not convinced about the wiring and I'm not electrically savvy enough to work it out! I'm hoping if I describe how it's wired someone can tell me if it's potentially correct so here goes:

The sender has two terminals one of which is connected to both the negative on the battery and to the negative on the fuel guage itself. The other is pink and runs to the S terminal on the guage. Finally the fuel guage has a positive coming from the rev meter.

One strange thing that happens - may be totally unrelated but worth a mention, when the ignition is on (not the engine) the rev meter needle rises up to about 1000 - the rev meter works fine though when the motor is running.

If anyone does understand what I'm rambling on about then I would very much appreciate some input. Thank you.

Best Regards,

Ralph.

 

eazy test key on power to gauges
pink wire removed from sending unit reads full sender ok
remove pink from back of gauge reads full bad gauge reads empty shorted wire

 

Thanks, does the way I've described the wiring sound correct though? I have removed the pink from the guage and it reads full - so by your reckoning the guage may be faulty, but I'd also read elsewhere that incorrect wiring could cause the same symptom.

 

yes the wiring sound fine if s terminal is empty and gauge is reading check and make sure positvie and negitive are correct and replace guage