I have a problem with dead gauges on my old aluminum fishing boat.
Last year the tachometer and gas gauges were the only two working. The speedometer, trim gauge, and volt meter did not work. As the year progressed, the tach started to stay in one place and the gas gauge stopped all together.
When looking at the connections for the gauges they are plugged into the back of the gauge except for the gas gauge which was replaced two years ago and it has wires connecting it to the boat wiring harness. I have checked and replaced all the fuses and looked for any loose connections that I could see.
What should I look for now?
Thanks for your help.
If they are all dead, it is probably a bad power or ground connection.
Using a meter of a test light you should be able to measure 12 volts between the purple and black wires on all of the gauges when the key is on.
Since this is an older boat, the speedo is probably a pitot style that works off of water pressure. Check the pickup on the transom to see if it is plugged.
Hope this helps.