Gravely intermittent wiring short

ILENGINE

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I need some insight in to what you guys think is causing the issue. this mower problem started with blowing the 25 amp fuse feed by the red wire on the diagram. After replacing the fuse it held and the customer used the mower for about a week. Then it came back in with both the brake switch and the pto switch prongs 3 to 9 bad. After replacing both switch about 2 weeks ago it has since returned with both switches bad again. Initial testing with a 10 amp tester resulted in the fuse inside the tester being blown, but between that fuse blowing and grabbing a higher amp tester the short corrected itself and now is showing .5 amp draw through the 3 to 9 wires with the key in the on position.

Any good guesses to where the intermittent short may be so I don't have to keep risking more switches to find the issue. I am thinking something goody with the key switch but if somebody else has thoughts let me know. the start relay is showing a resistance reading of 87 ohms, and the fuel solenoid is showing a resistance of 29 ohms, No strange shorts present with the key switch at this time and seems to be testing correct according to the key switch diagram. If you disconnect the all of the components that go to ground like the relay circuit, fuel solenoid, and the hour meter there is no continuity through the system so there shouldn't be any wiring shorts but cannot be ruled out I guess.

View attachment gravely wiring diagram.pdf
 

bertsmobile1

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Another wiring diagram drawn by some one who failed electricity in 3rd form.
The Auxilary power I am assuming is a cigarette lighter type power out plug.
If so that would be my first port of call.
Usually a fully grounded case with an insulated nut on the power wire, very prone to coming loose & going dead short.
 

ILENGINE

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No headlights or lighter plug. I was out playing with the wiring, and had the key switch on, and the meter set at volts, and was reading .5 volts which could be just stray voltage, but was trying to find the cause of the stray voltage and happen to wiggle the brake cable that runs next to a sleeved wiring harness, and the voltage started jumping around and finally hit a point where the voltage jumped to 12 volts so I at that point started working to get access to the wires and had to remove the sleeve so I could slide the harness between the rear of the engine and the frame, and after pulling the wires apart in the harness found a 1/4 piece of insulation missing from a wire. So I think that may be my short.
 
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