Blowing fuses on johnson 115

I recently took my fathers boat to the lake. We had to jump the battery and it ran fine. Well the next day when we brought it home to run it at our house we found that when we turned the key nothing would happen. (The battery is fully charged. Well when we got to looking around there was a fuse blown is the red wire that comes out of the ignition to the fuel guage. We cant figure out why it is blowing fuses. When the fuse is in the engine will turn then the fuse will blow. If you could help it would be greatfull.<br /><br />1977 Johnson 115 v-4

Re: Blowing fuses on johnson 115

rooskie,<br /><br />The simple answer is that you have a short somewhere.<br /><br />I believe the wire you are referring to simply energizes the fuel guage. The engine should run with that wire disconnected.

Re: Blowing fuses on johnson 115

Actually there is a wire that must come from the battery that supplies power to all of the guages. The red wire that comes out of the ignition splits about half-way one wire goes to the one of the terminals on the gas guage and the other one goes to an in-line fuse and then to the other terminal on the gas guage. And, the only way the engine will run is if the two wires are touching or the fuse isn't blown,but once the fuse blows, when you turn the key nothing happens. What would be the use of the first wire that splits off and goes to the gas guage, if you already have one wire going there too. <br /><br />If I did disconnect the wires where would the ignition get its power because it has no other source.<br /><br />We had all of the guages replaced last year so, we don't know if the guy re-wired it wrong or what? Does anybody have the diagram on this motor so I can see where the wires are suppose to hook up????

Re: Blowing fuses on johnson 115

I've got the wiring diagram for the engine but it's not gonna help ya with the gauge wiring. <br /><br />c/6<br /><br />Hooty

Re: Blowing fuses on johnson 115

rooskie,<br /><br />When you say ignition, do you mean the harness that plugs into the back of the control box, just under the key?<br /><br />If so, that is the tachometer harness (easily unplugs, three wires). You can unplug that from the control box and the engine should still run and start.

Re: Blowing fuses on johnson 115

Can somebody tell me what the little round green thing is in the control unit. Also can you tell me where the wires that run to the control unit start. Thanks