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Discussion Starter · #1 ·
After mowing for about 2 hours my 317 shut down suddenly. It had no problem starting right back up but then after a few minutes it shut back down. After trying some things I noticed it would only shut down with the PTO engaged. I also noticed the ammeter dropped to the negative with the PTO engaged even at WOT. Any thoughts?
 

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Kevin,

A known failure mode of the electric PTO is to have a shorted winding that shows up when the assembly gets fully up to temperature. The shorted coil will draw an excessive amount of current and trip breakers, blow fuses and generally cause electrical gremlins. If you can, unplug and measure the resistance of the PTO winding immediately after it shuts down. Normal values are in the 3.5 to 4.9 ohm range, but internal shorts can make it very much less...

Chuck
 

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I had a similar problem with my 314. I could mow for maybe an hour, maybe more. Then It would die unless I flipped the pro switch. It turned out to be a cut wire to the seat safety switch. It would run fine for a while then the cut spot would bet in the right position and it just stopped. Stop for a while and it changed position and would mow again. It was driving me crazy. You might want to check that. I
 

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Discussion Starter · #4 ·
I looked at the seat safety switch, all looks good. To test the ohms do i just pull the wire harness from the switch and test the wire that goes to the PTO to ground? If so it read 0. I also started it up and tested the voltage at the battery. Running with PTO off it was 14, as soon as I engaged the PTO it started dropping quickly until it got to about 10 then it shut off. All signs seem to point to the PTO coil.
 

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Kevin,
Check the wires on the PTO coil and if they are good, order a new one from Deere. About $110.00
You could look for a used one but it may not be any better than the one you have.
Dom
 

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Kevin, you are on the right track for testing the coil resistance. However, the easiest way is to pull the left side cover and the grill. You should find the coil to harness connector down low on the left side. Unplug it and plug one lead to the coil wire, the other to ground. The original KT17 usually would have only one wire. If you have an Onan replacement engine the coil may have two wires. If so, plug each of the ohm meter leads into the two wires.
Most likely the coil is bad or the hot wire going to it is frayed and touching ground.

tommyhawk
 

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Discussion Starter · #7 ·
After I got into it I verified it wasn't a bare wire by unplugging the harness and testing to ground. The coil had expanded and was rubbing the rotor. Now putting it back together does anyone know the torque spec for the spring bolts holding on the clutch?
 

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Kevin,

Could just be your meter -- many inexpensive digital ones are fairly accurate but occasionally a really cheap one is not that good, and the analog ones are VERY dependent on price and quality versus accuracy...does it read a true zero ohms if you short the probes together?

Even if the 2.4 ohms value is correct, that only works out to be 6 amps or so at the maximum system voltage of 14.3 volts. Not ideal, but should not cause any issues if it doesn't self-heat. That 6 amps works out to be about 150% of a "normal" draw...

Chuck
 

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Wire resistance is also related to temperature, as the temperature drops the resistance drops. Not sure of the size or amount of wire used in the coil but it does make a difference.

In the days before digital meters it was not a concern as the old analog meters would have difficulty reading to within 1 ohm or less.
 
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