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316 electrical problem

Mike Stefanik Long story but here it goes. I bought a john deere 316 w/ an onan p218 motor a few months ago. Its an 87 with 830 hours on it. After I mowed the grass the first time, about an hour. I disengaged the mower and immediately went to re engage it and nothing. Battery light also came on. Through this forum and my onan owners manual I went through the steps to diagnose the problem. Tested ac from stator and dc from regulator. My first question is when testing the stator am I suposed to test the leads together or individually. I get about 16vac individually (red wire from tester to stator lead and black wire from tester to ground). This same result before and after I have replaced the stator. I originally only got 1.5 dc from regulator(only about 12.5dc at battery). After replacing the stator and voltage regulator (getting about 2.8 from regulator now) I measure about 13.6 dc at the battery. Which according to the book im supposed to have between 13 and 14 dc. But im also supposed to be getting 13 - 14 vdc from regulator. Could it be that the magnets on the blower wheel have lost there magnetism after 22 years. PTO still works when I first start up tractor, but when disengaging and re engaging after extended use pto doesnt start. I still get drain (from battery) when turning on the pto, but pto does nothing, I get a little magnetism from it. Oh, I also replaced the battery. So im stuck, are these problems related? Do I need to replace the 600$ blower wheel??
bontai Joe Have yu checked the gap between the PTO clutch faces? They may have worn to the point that the maggnet can't pull them together across the gap when energized. By memory, I think the gap si supposed to be .018" at each of the spring loaded clutch adjustment screws. You will need to check each screw several times as adjusting one effects the settings at the others. Takes a little while to "dial it in".
Mike Stefanik That was one of the first things I checked, gap is what it's supposed to be.
Dale G. Basgall Mike : On the stator leads from the induction coils that the magnets effect to accumulate the electricity they should have continuity together but not to ground. The meter needs to be on the ac scale and tough both leads coming from the stator coils and to the regulator ac terminals. So you need to touch both the leads at the same time and they do not have continuity to ground.

Dale G. Basgall

Mike I did test them together as well, black lead in one connector red in the other (connectors from stator). I got between 32 and 38 vac. Does this mean stator and blower wheel are fine? That would be great considering blower wheel is expensive. Why then am I only getting 2.8 vdc out of a brand new vr? Thanks for everyones help so far!
Tony Bachler HI;; Engine off; Ignition on;hood closed; belt off mower. grab the grill on upper half give it a good pull remove it.Engine off; Ignition on , now flip the pto. switch of there will be a clicking sound from the clutch. with the switch on seeif you can turn the clutch. it shoulb be engaged and locked to the engine. Turn the pto off the clutch should spin free,The clutch should be adjusted Yearly. Feeler gage setting in the slot, The potental voltage is the difference between the leads. OH IT IS DC;
Dale G. Basgall Mike : If you checked out the stator leads and have 32 to 38 vac. then your stator is fine. So at the regulator lead with the ignition switch on you should get a reading of source voltage or battery potential. When the engine is started and your dvom attached to the battery the voltage should rise slowly.

For example, 12.48vdc at the batery with the engine off and as the leads are still attached turn on the engine and the voltage should rise slowly, not like a car alternator though. The voltage should continue to rise until it gets to around 13.2vdc or so at the battery and then turn on the pto as the engine is running and watch to see if the battery voltage starts dropping instead of climbing.

It is unlikely the pto is shorted but take a resistance reading between the two pto leads with the pto unplugged. You should get a reading of about 40 to 60 ohms on that one I think.

If the reading is lower, just send the results back on the forum and I will look up the pto resistance.

Do this, take the ohm reading and divide volts by the ohms and that equals the current in amps, if the current draw in amps is more than the rated output of the regulator the battery will always die eventually. Send back the readings on the output of the regulator, something there seems not right , I saw on your first post a NAPA number and I am wondering if it is grounded properly ?

Should you need further assistance please write back on the forum.

Dale G. Basgall

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