Suzuki commander gauges help

[jasonbs8307]

I have suzuki commander gauges on my 2004 robalo 260 walk around. When i bought the boat last year it had been repowered in 2005 with twin 250 suzukis and new comander series tachs and a speedometer. The speedometer gauge doesnt work the depth finder doesn't work(blinking this: depth-------), the tachs show no fuel flow and even with a full tank the fuel level reads all different readings. The tachs do read the rpms properly but thats about it. the birdsnest of wire under the dash is rediculous but it all looks to be connected properly. Is it possible that both transducers on the fuel lines, the transducer for the speedo, and the fuel level sending unit all dont work. Just to clarify none of the above have worked since i bought the boat.