Blowing Main engine fuse problem

[svillebrian]

Just recently started having a problem blowing the main fuse located in the wiring on the motor. I have a 2001 Johnson 90hp 60 degree. I put a test light on the fuse plug, and getting power to one side of the connecter and the other side is grounded, causing the fuse to blow. My main question is where do the two red wires on the fuse connector go (or tie into to) so I can try to trace where the one side of the wire is grounding out? Any help is greatly appreciated!!

 

[seahorse5]

Re: Blowing Main engine fuse problem

Unplug the boat wiring harness from the motor and temporarliy hook up a different one to find out if the short is in the motor or in the boat wiring.

Does the fuse blow as soon as the key is turned on, turned to start, or when the "choke" is pushed in?

The red wires on the fuse holder go from the starter solenoid battery cable post ---> fuse ----> to keyswitch

 

[svillebrian]

Re: Blowing Main engine fuse problem

The fuse is blowing with just the key in the on position.

 

[svillebrian]

Re: Blowing Main engine fuse problem

Just went and checked on it again. Key off - power on one side, no ground on the other. Key in on and start, power on one side, ground on the other. Put a new fuse in and it didnt blow it yet, but it has been blowing them regulary on and off for a week now? Could I have a ground in the wire going to the key switch, or could the key switch itself be gounding out?

 

[seahorse5]

Re: Blowing Main engine fuse problem

The most common fuse blowing problem like yours is normally behind the dashboard where the purple wires may touch a ground wire.

Another, but hard to find problem, is in the boat wiring harness where a screw might rub or short out some wiring, usually in an inaccessable place.

Was any work done to the boat, or anything changed or installed before this started happening?

 

[Chris1956]

Re: Blowing Main engine fuse problem

Brian, My '98 Johnny 150HP 60* V6 has the same issue. I found melted wires in the boat harness where it connected to the engine on the port lower side of the cowling. I also found melted wires under the dashboard where the purple ignition accessory wire (12V DC) melted and shorted to the black (ground) wire where it plugged into the trim gauge. The trim gauge was the first of the gauges and power and ground to the others were daisy chained off of it.