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sjgriz4

No spark on my Onan 16

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sjgriz4

I had a problem the other day with my drive belt went bad, pushed it in the barn and replaced it and now for some reason I do not have any spark going to the plugs.  Any suggestion? 

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Cable

I would start by confirming that there is at 12 volts going to the coil with the switch on.

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sjgriz4

No it did not have 12volt, around 8.  Does this mean the coil could be bad?

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Jeff-C175

Griz, what is the voltage at the battery itself?

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sjgriz4

12 volt at the battery and 8.34volt on the incoming of the coil

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sjgriz4

I just went out and checked it again, and I have 9.34volt on the primary of the coil and and 11.78 volt at the battery. 

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Jeff-C175

Since Onan, safe to presume a 520 ?  what year?

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sjgriz4

1989 P216 Performer in a 418-8 Wheel Horse, I am at a lost here.  I ran down the safety switches and they were all ok.  In my mind it is one of three things, the battery is to weak, coil is bad, or new wires.  I also just replaced the plugs with RC 12YC Champions because that what it had in it, but after reading the manual that I just downloaded it calls for RC14YC plugs.  I don't know why they had diffrent plugs in it when I bought it and ran good just a little rough at idle.

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Jeff-C175

418 ?  Do you mean  416 ?

 

If you have 12 V (or thereabouts) at the battery, and only 8 V at the coil, then you are losing voltage somewhere along the line.

 

Either the ignition switch, the PTO switch, the connector, etc...

 

If all the connections are good, you should have the same voltage at the coil as at the battery.

post-10366-0-67106000-1372556795_thumb.j

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Jeff-C175

On the spark plug, all other parts of the plug number being equal, the 14 is the next step hotter plug.

 

You probably won't see much difference, but next time you change plugs, put the correct ones in.

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sjgriz4

Yes I meant 416, so if I am losing voltage somewhere then the best thing would be to start at the fuse after the battery and starting working my way to the coil to find out were the problem is.

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Jeff-C175

By the way, your battery voltage is a bit low, but this could be because you were cranking a lot and no start. 

 

Whatever you do, don't fry the starter!  Don't crank for more than 10 seconds and let the starter cool for a minute or two in between starting attempts.

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Cable

Ignition_zpsc584e29b.jpg

 

 

I think there likely is a bad connection somewhere in the path to the coil. A simple test is to install a jumper from the battery positive terminal to the coil.  If you then get spark, you know that there is a fault in the path going to the coil. The diagram here shows the path, except for the 9 pin connector. The coil's voltage passes through pin #6 of that connector, shown as dark blue on the drawing but don't be surprised if it is yellow.  It may be one color on one side of the connector and another on the other side.

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Jeff-C175

 

if I am losing voltage somewhere then the best thing would be to start at the fuse after the battery and starting working my way to the coil to find out were the problem is.

 

Exactly.  Put your meter negative on a good ground.  Go from point to point along the circuit with the positive until you find the culprit.

 

One thing that you could check...

 

With the meter on the + side of the coil and the PTO switch OFF, and NOT in the seat (seat switch OPEN), measure voltage.

Then, operate seat switch and see if voltage changes. 

 

When NOT in the seat, and PTO in OFF, the coil will get voltage through PTO switch only.

 

Since the seat switch is in parallel with the PTO switch, if the PTO switch is dropping voltage, by rocking the seat switch you would see a difference (as long as the seat switch is good).

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Jeff-C175

 

The coil's voltage passes through pin #9 of that connector,

 

Drawing I'm looking at shows pin #6 ?

 

1989 - 416-8 ?  page 7-68 of the demyst manual?

 

I think you're looking at the 87-88 model... this is an 89.

 

Cable pointed out that there is a connector not shown in either his or my diagram, so don't overlook that when checking.

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Cable

My mistake.  It is pin 6.

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Jeff-C175

Griz, if you don't have the diagram, download the guide here:

 

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sjgriz4

Thanks for the PDF file, to be honest I didn't know what you guys were talking about "6pin" and "9pin".  I am downloading it now and going to read through what I can tonight and take a look at in the morning and hopefully I can have it figured out before afternoon comes around.  Thanks for all the help and I will let you guys know what I find out tomorrow

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sjgriz4

I have tried to download the file but it is to big I guess, keeps timming out on me.  :)  Can you send it to me in an email @ sjgriz4@aol.com

 

Thanks

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Jeff-C175

Sending via email now... 30 megabytes... hope it makes it!

 

Nope...  file is too big for my email to send...

 

I wish I had a way to pull individual pages from the demystification manual that apply to your machine... I don't know how to do that though...

 

Wait... I figured it out... emailing now, MUCH MUCH smaller file!  also, attaching here, I think... yes, that worked... also uploaded to manual section file name " Tractor 1989 416-8 Wiring Detailed #492-4509.pdf "

 

Tractor 1989 416-8 wiring.pdf

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sjgriz4

 

 

if I am losing voltage somewhere then the best thing would be to start at the fuse after the battery and starting working my way to the coil to find out were the problem is.

 

Exactly.  Put your meter negative on a good ground.  Go from point to point along the circuit with the positive until you find the culprit.

 

One thing that you could check...

 

With the meter on the + side of the coil and the PTO switch OFF, and NOT in the seat (seat switch OPEN), measure voltage.

Then, operate seat switch and see if voltage changes. 

 

When NOT in the seat, and PTO in OFF, the coil will get voltage through PTO switch only.

 

Since the seat switch is in parallel with the PTO switch, if the PTO switch is dropping voltage, by rocking the seat switch you would see a difference (as long as the seat switch is good).

 

Ok here is what I checked this morning:

 

With the meter on the + side of the primary of the coil I toggled the seat pan and got a little drop around .3 volts.

With the meter on the + side of the primary of the coil I turned on the PTO and the voltage dropped to little to nothing

With the meter on the + side of the primary of the coil I pushed in on the clutch and no change.

This to me tells me that all three safety swithches are working, am I correct?

My battery charger took a crap but I do have a tender and sent a text to my neighbor so I can get his charger to get the battery completely charged to eliminate that the battery could be bad.

Then I will look at the wires being bad or the coil

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Jeff-C175

 

With the meter on the + side of the primary of the coil I toggled the seat pan and got a little drop around .3 volts.

 

It would help us understand a little better if you told us what voltage you were actually measuring at this point...

 

 

This to me tells me that all three safety swithches are working, am I correct?

 

Maybe... maybe not.  It is telling you that the switches are working to 'some degree', but not whether or not they are actually making a 'clean contact' with no resistance.  It's possible for a switch to be making a 'partial' contact with high resistance, and this is where you would be dropping voltage.

 

See if you can locate the " I " terminal on the ignition switch and with the key in "RUN" tell us what voltage you have at that point.

 

Is it possible that during the course of the belt replacement a grounding jumper was removed and 'accidentally' not reconnected?  Since this occurred after changing the belt, you should be looking for 'shyte happenz' if you know what I mean.

Even if the battery is not up to full charge, you should have the same voltage on the + terminal of the coil as you do at the battery.  There should be no voltage drop in the wiring or switches.

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Jeff-C175

 

Is it possible that during the course of the belt replacement a grounding jumper was removed and 'accidentally' not reconnected?  Since this occurred after changing the belt, you should be looking for 'shyte happenz' if you know what I mean.

 

Where are you connecting the ground wire for the meter?

 

On the engine or some other metal part that should be ground?

 

IF SO, move the meter ground wire to the battery negative post and see if anything changes.

 

If it DOES change, it means that your problem is somewhere in the GROUND wiring, and not the positive side.

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sjgriz4

The ground wire is connected to the negative side of the battery.

 

 

When I tested the battery and the point at the coil it read 11.9 volts, the good charger is on the battery now and is says that the battery is at 82%

 

I got 11.94 volts at the "I" terminal

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Jeff-C175

 

When I tested the battery and the point at the coil it read 11.9 volts

 

If you now have the same voltage at the battery and at the coil, that is what you SHOULD have. 

 

Why it was much lower before is a puzzle... could mean intermittent bad connection in the PTO switch.

 

Your recent email seems to indicate a FUEL problem now though.

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