# Jd 300



## don9724 (Aug 23, 2011)

Hi All!

I have a 300 with a Kawasaki and it just wouldnt start one day. It would turn over fine, but no spark. I disconnected one of the coils and it started right up. I reconnected the coil and disconnected the other coil and it started right up. But wont start with both connected. I was told there is a diode between the 2 coils but for the life of me I dont see one. It looks like its just a plain old stranded 18ga wired between them. Any thoughts? The code on the engine is FH491v if that helps

Don


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## jhngardner367 (Apr 5, 2011)

Welcome to the forum,Don!
If I remember,correctly,the diode is in the harness that feeds to the coils. It prevents each cylinder from firing out of time,by preventing the electrical power from flowing the "wrong" way.Much like the diode Briggs uses ,to change ac current,to DC current,for charging the battery.
If you trace backward from the coils,to the connector at the harness,you should find a "lump" in the wire.That should be the diode.Some models had one for each coil,so look for two.


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## don9724 (Aug 23, 2011)

Thanks for the quick reply,
I traced that wire all the way back to the ignition module and couldn't find a diode any place. I took the wire completely off and laid it out on the table, metered it in both directions, then up to the ignition module, couldn't find any diode. It makes sense that it would have one but for the life of me I cant find it. Is it possible its the ignition module? Thats the only thing left

Don


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## don9724 (Aug 23, 2011)

*JD X300 Solved*

Ok, Its all set. It was the ignition module. John Deere has been having issues with these modules and the replacement has a new part number AM141075.

You can test if it is this module by disconnecting it then on the side by the starter you will see a white wire with a green tracer and it has a disconnect. Pull it apart and run a jumper from the engine side to the positive on the battery. When you start it all should be fine if its the module. Once you have done this you will need to disconnect the jumper from the positive side of the battery to shut it off.


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