Won't stay running John Deere Z997 ZTR Mower Year 2008

[feoneill9]

Rethinking JD. 3 people in Europe, 3 or so people in the US and 2 people at the JD dealership could not have been nicer to me and helpful. That has to indicate a caring organization.

Your are right I have a problem and I have to fix it. The fickle finger of fate has reached out to me- deal with it.

So I am off to work on it without the blaming or other stuff.

I appreciate every ones help and thoughts.

 

[Coyote machine]

People misname 'shorts'. A bare wire energized with 12 or more volts when contacting bare or painted metal will blow a fuse if one is in the path the wire travels from it's hot source, or it could cause a fire in the harness, or excessive heat if not part of a fused link from the voltage source.
You could have an intermittent 'open' where a wire is not completely broken in its path to whatever circuit completion it should be making, OR where the wire has only a few strands completing a particular circuit.
Sounds like a real nightmare of wires, too many switches and relays, all combined to make troubleshooting without the correct diagram and 'key' adding to the confusion.
You could try moving around the wiring that is accessible to see if symptoms change.

 

[Richard001]

Does this engine have mechanical or electronic fuel injectors?

Richard

 

[feoneill9]

Hi Richard001:
Almost certain they are mechanical. It has an mechanical injector pump.

I am trying to find out where the wires from the PTO dash knob go to turn the mechanical blade drive transmission on. Could be that that connection is bad.

I am at my wits end on this one. Your assistance is appreciated.

This morning I bought 2 relays at the JD dealer. As soon as I gave the part number to the counter man he shouted to a customer. "Here it is the relay you need monday which we could not find the number". The customer had a machine stuck in the field and they could not get a relay for the old electronic gear not supported by JD any more. Even the mfg of the electronic would not sell them the part as they were not a dealer. It costs the customer $1,300.00 to get the machine rewired to work around the problem. He was happy that they got it fixed.

That is what I am trying to avoid an open ended repair job at $85.00 an hour and no income from the machine. At least he had a harvest of wheat to get cut,

 

[Coyote machine]

Can you disconnect the wiring going to the deck to see if the mower keeps running, and thus diagnose what you think may be the PTO engagement switching prior to just buying and replacing more relays/switches?

 

[feoneill9]

Thanks for the reply.

The colored wires were I think they enter and control the deck transmission blade drive do not show up on the PTO knob on the control panel. They must change colors some where in the wire looms.

I have ordered the Tech Ser Manual but it will be another week before it gets here.

The best solution for know is to just wait.

 

[Richard001]

Almost certain they are mechanical. It has an mechanical injector pump.

OK, now we know that the reason the engine stops is not because of the injectors. Well I guess it could be as I's sure that there is a solenoid that enables the mechanical injector's.

Here is my suggestion. Try to isolate the problem. Take and hot wire 12v to the injector solenoid. Start the engine. See if it stays running.

Most fuel shut off solenoids have two coils. One is a pull-in and the other is the hold coil. The diagram I found shows that one side of the coils are common and are grounded in the solenoid, so your shut off solenoid most likely will only have two wires going to it.

Unplug the solenoid from the harness and momentarily touch 12v to one of the wires in the connector. If you hear a click when you do this, that means that wire is the pull-in coil. Caution, do not leave 12v connected to the pull-in coil for more that a few seconds. Otherwise it will burn out.

When you determine which wire is the pull-in coil, then connect 12v to the hold coil and then momentarily connect 12v to the pull-in coil. You fuel injector will now work.

Let us know how this works for you.

Richard

 

[feoneill9]

I checked the fuel. The fuel solenoid works correctly. Fuel is always flowing to the engine. The unit has a low pressure fuel pump that pumps fuel into the fuel/ water filter and it starts as soon as the key is turned to run just like the engine fuel solenoid.

I noticed that the unit has a place on the hydraulic pump with two wires leading into it. The wires are both blue - blue wires lead from the starter. With the key turned on both wires are hot. I checked them with a wire probe. Why would that be- it would seem to be a real short circuit situation? With the engine running and the wires disconnect the engine continues. The PB, Levers shut it down and the PTO engagement does not start the blade transmission to run the blades . Could it be a heater? No drawing shows these wires.

I checked all ten of the relays - including the one with 2 blue wires in and 2 wires( like on the started and the hyd. pump) out and they all work properly with the wire probe.

The unit has a Seat Time delay and you can not check it- I don't know what it does.

Also the unit has two solenoid devote to Latch Relay 1 and Latch Relay 2 and I do not know what they do. Also has a Pull In Relay and I don't know what it does.

Keep those cards and letter coming and the thoughts.

You have to love John Deere.

 

[feoneill9]

Hi:
Well are of the hydraulics are operating properly. I checked the Hyd oil solenold, temperature ,pump and motors are check out OK.

I have never been able to find more that 2 of the 3 purpule wires fron the PB and Levers safety switches. 2 of the wires appear on a replay and check out OZ.

Today I discovered the third wire. It is attached to the starter motor, actually the solenoid. I can not test it until I can get to unpluged. It sits under the engine along side the frame and above the hyd oil filter. I can get to it if I remove the oil filter and drain 6 gallons of hyd. fuild! I believe that a gallon is 48 bucks. It could be a short some where in this wire and it shut down the engine withe the engine running and the safety switches in neutral and they are moved to engage.

Any thoughts?

Thanks for the help.

 

[Richard001]

Got a wire cutter? Use it. A lot simpler than what you are thinking.

Richard