Help. John Deere D140 wont start.

JD_140

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I have a John Deere D140 that wont start. Last fall I turned it off to answer a phone call and it would not start back up. I had the blades engaged without turning them off when I turned the ignition key off. Would not attempt to start after that. I am now trying to get it going. I can turn the key to on and jumper 12volts to the starter and start it, it then runs fine. It just wont start on its own. There is a 30amp relay that (i think its called the start relay) works. I removed it and could apply 12 volts to the coils and check the Normaly Open, and the Normaly Closed section. They go opposite with voltage applied and I can hear the relay work. The power from the battery comes down to a big relay and then that goes to the starter. I measured the coil connections on it and I dont ever see 12 volts there. The wires going to that relay's coil looks like it goes into a bundle that is going to the rear of the lawnmower and I cannot tell where.
I dont have any kind of wiring diagram and that is hindering me. Its almost like an interlock switch is causing this problem. Does anyone have any suggestions??
 

JD_140

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I have a John Deere D140 that wont start. Last fall I turned it off to answer a phone call and it would not start back up. I had the blades engaged without turning them off when I turned the ignition key off. Would not attempt to start after that. I am now trying to get it going. I can turn the key to on and jumper 12volts to the starter and start it, it then runs fine. It just wont start on its own. There is a 30amp relay that (i think its called the start relay) works. I removed it and could apply 12 volts to the coils and check the Normaly Open, and the Normaly Closed section. They go opposite with voltage applied and I can hear the relay work. The power from the battery comes down to a big relay and then that goes to the starter. I measured the coil connections on it and I dont ever see 12 volts there. The wires going to that relay's coil looks like it goes into a bundle that is going to the rear of the lawnmower and I cannot tell where.
I dont have any kind of wiring diagram and that is hindering me. Its almost like an interlock switch is causing this problem. Does anyone have any suggestions??
Wow..... JD wants $154 for a manual !! What a rip!!
 

StarTech

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Considering how well written the service manual is it is worth especially since it cover 11 models.

So what year is the mower? There two different wiring diagrams base on when it was made. Make that three versions.
 
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JD_140

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Considering how well written the service manual is it is worth especially since it cover 11 models.

So what year is the mower? There two different wiring diagrams base on when it was made. Make that three versions.
DOM is 022217 so I assume it is a 2017 model.

After working on this mower most of the day, I got tired of trying to find the interlock switch that is causing the issue so I just bypassed it. I defeteated the reverse safety switch when I first got the mower so..... I just wired 12 volts thru that switch and use it as a start switch. Conviently it is just a momentary switch and works great.
 

JD_140

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Considering how well written the service manual is it is worth especially since it cover 11 models.

So what year is the mower? There two different wiring diagrams base on when it was made. Make that three versions.
DOM is 022217 so I assume it is a 2017 model.

After working on this mower most of the day, I got tired of trying to find the interlock switch that is causing the issue so I just bypassed it. I defeteated the reverse safety switch (RIO) when I first got the mower so..... I just wired 12 volts thru that switch and use it as a start switch. Conviently it is just a momentary switch and works great.
 

JD_140

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It looks like the signal to energize the starting motor goes from: S1 (Key) thru S2 (PTO switch) thru S3 (Brake switch) thru S6 (Reverse switch) then to the Starting Motor solenoid.
You don't by chance have a diagram showing where S6 and S2 are do you?

I can follow wires if need be, it's a little bit tricky to see under the chasis. I would imagine S6 is in the rear near the transmission. I would guess S2 is near the PTO cluch.

I VERY much appreciate the wiring diagram.
Thanks again,
Frankie
 

StarTech

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These are sorta obvious. The PTO switch is the one on the dash since this an electric PTO setup. And the reverse switch will at the rear attached to the transaxle. Kinda looks like be on the right of the transaxle. Can't narrow it down beyond that as I haven't a D140 in the shop yet.
The bracket Item 30 is #1 arrow and where it is attached is #2 arrow. The switch should be activate by item 33.
1710518175701.png
 

rhkraft

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I have a John Deere D140 that wont start. Last fall I turned it off to answer a phone call and it would not start back up. I had the blades engaged without turning them off when I turned the ignition key off. Would not attempt to start after that. I am now trying to get it going. I can turn the key to on and jumper 12volts to the starter and start it, it then runs fine. It just wont start on its own. There is a 30amp relay that (i think its called the start relay) works. I removed it and could apply 12 volts to the coils and check the Normaly Open, and the Normaly Closed section. They go opposite with voltage applied and I can hear the relay work. The power from the battery comes down to a big relay and then that goes to the starter. I measured the coil connections on it and I dont ever see 12 volts there. The wires going to that relay's coil looks like it goes into a bundle that is going to the rear of the lawnmower and I cannot tell where.
I dont have any kind of wiring diagram and that is hindering me. Its almost like an interlock switch is causing this problem. Does anyone have any suggestions??
You didn't say if you disengaged the blade. I had a repair call once and that is what it was. He lifted the blade, but not all the way. When he asked what he owed me, I said $50, but it would be free if he didn't mind being embarrassed. He said, Oh damn, what did I do???
 
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