On a week long fishing trip last month I blew all my engine gauges but 1 and blew my fishfinder. Before replacing everything I would like to have an idea exactly what went wrong and how to prevent it in the future. I am not sure if everything blew at once or one at a time. I am pretty sure something I did was the root of the problem, let me explain and see if someone can figure out exactly what happened.<br /><br />Let me start by saying my engine tach had been acting up off and on for a couple of years, all the other gauges were in good working order before the trip. I suspect I caused the problem on the 3rd day of the trip. I had been fishing and running the livewell, bilge pump and electronics for a couple of hours. When I went to start the engine the battery was dead. I don't have a battery selector installed (I soon will have) so I manualy switched batteries and started the boat. I wanted to charge the dead battery so with the boat running I swaped back to the other battery. I don't know exactly when my gauges blew but I suspect they were working at this point because I'm sure I would have looked at the volt meter after doing this. Anyway later I noticed the needle on my fuel gauge jumping from empty to full about every 2 seconds. At some point later in the trip I noticed my fuel gauge, volt meter, Tilt/trim gauge and engine tach were all out. My water pressure gauge still worked but I believe it doesn't work on electricity. Also my fishfinder was blown, it is on the same circut my radio is on but the radio is ok. The radio was turned off most of the time tho and the fishfinder was on. I fished the rest of the week without gauges and the engine ran fine.<br /><br />When I got home I checked out the wireing and it all seemed good. I was getting the readings on my tester that the manual said I should get. Then I tested the gauges themselves and they are all blown so I know it is not a bad ground. Has anything I have posted given a clue as to what happened? What I am wondering is if I blew the gauges by spiking the electrical system or if I somehow damaged the engines charge system which later blew the gauges? If it is the later I am afraid I would be asking for it to happen again if I replace the gauges.
