John Deere R72 wiring

jakesmurray

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I am working on a JD R72 rider for a old lady. The engine shuts off when you turn the blades on, so I am wondering how I go about disabling the safety switch? I have already cut off the switch, and now there are two purple wires, a white wire and a black one. You would think that you would just connect them to one another to complete the circuit, but I think I have tried every possible combination, and the starter still does nothing. Anyone know how to bypass this switch? Thank you
 

reynoldston

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I posted this just a little earlier but here it is again. Switches can be two ways to work open or closed. By putting the wires together you are making a circuit to turn off the mower. You want it open.
 

jakesmurray

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I posted this just a little earlier but here it is again. Switches can be two ways to work open or closed. By putting the wires together you are making a circuit to turn off the mower. You want it open.

So it's just a matter of figuring out which ones should be left open and which ones if any should be connected?
 

reynoldston

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So it's just a matter of figuring out which ones should be left open and which ones if any should be connected?

To turn the mower off they use negative power which is a wire to the chassis, so yes open. Everyone always thinks of the positive but everything has two powers to it and never thinks about the negative power. The reason is they use the chassis for the negative side and no one gives it a thought that the chassis is one big wire.
 

jakesmurray

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To turn the mower off they use negative power which is a wire to the chassis, so yes open. Everyone always thinks of the positive but everything has two powers to it and never thinks about the negative power. The reason is they use the chassis for the negative side and no one gives it a thought that the chassis is one big wire.

Well, I have tried it with all the wires open, but still nothing happens?
 

KennyV

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I can think of two things...
First you are not helping a "old Lady" by disabling a safety switch....
Second if you have 'accidentally' applied 12 volts to the magneto it is not going to start, you have fried the magneto...
You really Need to check the wiring diagram Before you start shorting things out... Trial & Error is expensive when it is on your equipment... let alone someone else stuff... :smile:KennyV
 

reynoldston

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You really Need to check the wiring diagram Before you start shorting things out... Trial & Error is expensive when it is on your equipment... let alone someone else stuff... :smile:KennyV

KennyV has said a lot here and I am seeing this all the time on this forum. Just keep trying parts. I think another problim is that not everyone can read a wireing diagram.
 

jakesmurray

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Where can I find a wiring diagram? The whole reason I am disabling the switch is because when you would engage the blades, the engine would shut off, so something wasn't right. When I jump the two contacts on the solenoid with a screwdriver, the starter engages just fine and it fires right up. I guess I just need a wiring diagram now.
 

jakesmurray

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Ok, I got it figured out. There was a fuse that had blown, so it was not making a complete circuit. Now it starts up and runs great with the key. Thanks
 
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