Sea Ray

Sundancer370

On my 1995 Sundancer the Fuel & Tach gauges are unreliable.

Fuel gauges; Always show low fuel level & show different to each other even when I know physically that Iv'e just filled both tanks.  

Can anyone advise a simple way to determine if its the Tank Sending units or the gauges which are at fault, I took out the Stb'd sender and its just a cork float on a rod with the sensor unit on the top connecting to the tank closing plate. I clamped it to to the side of my workshop water tub and filled the tub, the rod lifted with the rising water so that doesn't seem to be the problem but I'm not sure if the sensor is working properly because it doesn't make any kind of noise or clicking to indicate it is sensing the rising or lowering water level.

Ref the gauges themselves, I removed the dash bezel cover to expose all the gauges backsides then disconnected "all" gauges wiring one by one and cleaned all connections best as I could with a small wire brush and emery cloth etc and reconnected them again.                      All gauges appear in good order physically and visually etc but am not sure about actual performance, I am suspecting that it is the gauges at fault (possibly just the age factor) as the sending unit is a simple cork float on a rod but need to know how to test one against the other to find if its the sender sensor or the gauges themselves. Iv'e read on different sites that Searay gauges are notorious for being inaccurate.

Tachometers; Similar as above for Tach's, they never show same rpm when both engines equalized on center paralleling guage so difficult to know which one is correct or even if one of them is correct that is. Big discrepancy in rpm's showing btw'n port & stb'd guages and stb'd gauge flicks around heavily when gauge bezel is tapped.  

Ref both above, if these gauges were even reasonably close to each other I wouldn't be too concerned "especially the fuel gauges" but there is a wide discrepancy between them which doesn't give a good comfort feeling when one is showing almost empty and one is showing just a third full !!  when I was sure I had more gas than that out in middle of Lake Ontario with still about 5hrs to go to get home.

I'm sure these situations have been experienced by many boaters so am hopeful to receive comments to determine how to test whether its gauges or sending units at fault to be able to source the correct replacement items. 

Cheers;