John Deere 757 Zero Turn Shut Off and Won't Turnover

[Oceancrosser]

My wife was cutting the grass and the mower stopped. Not the "I am out of gas stop) There was no fuel starvation, just quit as if a safety relay failed. I replaced the parking brake relay, both relays for the arms and jumped the seat safety cutoff. I ohms tested the old relays and all work as advertised!

When I go to engage the starter... nada... nothing, not even a "click". The battery checks out (12V) and I have power to the starter solenoid.

I have recycled the PTO and you can here it "click" on and off. (Of course the PTO is off for start)

What am I missing??? Is there a super secret safety relay I am overlooking?

Thanks,

Rusty

 

[Bertrrr]

I've tried to bypass all the safeties before and didn't work for me, ended up pulling the relays all together and rewiring my machine without all the safeties and ended my headache - pretty sure the relays are in Series so each one needs to satisfy the next etc.
Jump your solenoid and verify the starter will engage first then work back from there - ignition switch etc.
If jumping the solenoid does not work , it's probably a ground.
Odd that it stopped while mowing though , will the machine turn over by hand ?

 

[Oceancrosser]

I've tried to bypass all the safeties before and didn't work for me, ended up pulling the relays all together and rewiring my machine without all the safeties and ended my headache - pretty sure the relays are in Series so each one needs to satisfy the next etc.
Jump your solenoid and verify the starter will engage first then work back from there - ignition switch etc.
If jumping the solenoid does not work , it's probably a ground.
Odd that it stopped while mowing though , will the machine turn over by hand ?

yes, it will turn over by hand, meaning the engine is not seized. I was afraid the safety solenoids were in series so I replaced all of them.

I am going to clean up the grounding locations and hope for a better result!

Thanks for your help.

rusty

 

[bertsmobile1]

The circuits that prevent the engine cranking is usually the parking brake & the PTO switch
So you can not crank if the brake is not applied ( lap bars out ) and the PTO is off
On ZTR's it is usually a daisy chain on the + side so a power circuit
On ZTR's often it is split into 2 circuits
A power circuit from the key switch through the PTo to the + trigger on the solenoid
A ground circuit through both lap bars to the ground trigger on the solenoid

Where relays are used then the ground can be to a relay that energises the trigger connection on the starter solanoid
I unfortunately do not have the JD tech manual for your mower so I can not tell you for sure or post the wiring diagram

I will however suggest that you get one .
In fact all JD owners should get the JD tech manual
It will show you how to check the circuits, where to test the circuits and where all the bits are hidden
They are very comprehensive , often going over 500 pages with lots of photos so a person what has never touched a screwdriver can do the most complex repairs .
In fact their engine manuals are better that the engine makers manuals
Not free but most are around what a mower shop would charge you for 2 hours of work.
So the first time you use it in place of taking the mower to a repair it it has paid for itself
I buy them for every JD that my customers have and my only regret is I had the repair run for 3 years before I bought the first one.
Had I bought them from the get go my early days would have been sooooo much easier and a lot more profitable
The closest I have here is for the F 655 ( 1998 )

 

[StarTech]

Did the OP check the lap bar switches?

 

[Tiger Small Engine]

Did the OP check the lap bar switches?

They are safety switches, not relays, quite a difference. If you tested all the safety switches and they were good, why did you replace them? Electrical issues can be frustrating. If you have done all you can, then take it to a shop and get repaired.

 

[bertsmobile1]

According to the JD IPL the 757 has 4 relays
Magneto, Starter, PTO & Brake