John Deere 757 Z Track wiring diagram

[Auto Doc's]

Hello folks,

EDIT: This turned out to be a 2nd help request because the original one did not show up when I searched earlier.

This site is clunky at best.

I have an early serial number JD 757 that I am working on for a customer, I need a wiring diagram for it. The only one I could locate online is blurry and incomplete. Specifically, I am dealing with a red square block, plug in harness diode that is usually found on most large JD riders and zero turn mowers. The one on this mower tests bad with a multimeter.

I am not a fan of jumping safety switches and only do so for testing purposes. Currently I have the seat switch jumped and the diode removed so I can operate the mower.

 

[StarTech]

A shorted diode and allow the brake relay to kill the engine if the seat is jumpered. BTW JD run voltage thru the seat switch to activate magneto relay, Due to this these seat switch to burn out.

 

[Auto Doc's]

Yep, the diode is shorted (failed) internally, the PNP material has failed and not resistant in only one direction. The multimeter tests .000 in both directions and I have removed it for now so I could run the machine and test the rest of the systems.

My customer wants me to simply (recklessly) bypass the seat switch and leave the diode out, but I cannot blindly accept the liability for their "convenience".

 

[StarTech]

Diodes are PN junctions and not a PNP or NPN junctions. Transistors are either PNP or NPN junctions.

Replace the seat switch as it activates the Magento kill relay and the carb fuel solenoid. The diode only allows the mower to be started without the operator in the seat with brake depressed and the PTO switch off.

Yellow 401 wire switch 12v, Black 100 is ground of course. White wires 950 and 960 are the magneto kill wires.

 

[Auto Doc's]

Thanks Star Tech,

You are correct, a diode is a PN junction.

I have mixed the terms up for years (not and engineer), but I know a diode is a one-way door for electron flow unless it fails, then the door is wide open. (DVOM reads continuity in both directions)

Do you have a complete diagram? This partial one is at least clearer than what I could find online.

I'm correcting several (rigging) problems and replacing original connectors and pins as I go. I found a partial salvage harness, but it is worse than what I already have.

 

[StarTech]

I hate this Damn website. Crash my system 10x trying to do an upload to the site.

Try this link instead
https://drive.google.com/file/d/1jYRkY19q-SstUyNgIOHW_C0dHzZWYAsD/view?usp=sharing

You should be able to zoom in and/or download the file.

 

[Auto Doc's]

Thanks Star Tech,

I managed to play with the settings a little and got a more legible copy from the link you sent.

 

[StarTech]

Google displaying at about 50%, with Soda at 88% is all I can get on my screen and still see the whole image at once. Zooming 100% or higher it become more clear but I don't a full image and have move the image around to the area of interest. I did try go to 800% and it is crystal clear.

Note Abode Reader no longer work on my Win 7 Pro system. I also use a different program to extract the desired page(s).