OEM Ignition Switch for ZD326 Worth the Extra $70+?
- Thread starter Mr Haney
- Start date
Ok, I think this means that the stop solenoid has to be powered all the time for the engine to run. And stops the engine when power is removed. This is better from a fail safe perspective. On my tractor the solenoid has to be powered for a few seconds to stop the engine.
Stop solenoid is also controlled by the controller (orange wire).
Interesting fact I just learned: the manual's test resistances for the relays are wrong, so it's no wonder I thought my relay was bad.
Here is a corrected list:
85-86: ~90 ohms (coil)
87-87A: infinite (can't touch)
87-30: infinite
30-87A: 0 ohms
In addition to this error, I think the guy who wrote the Japanese manual also wrote the English version.
To say this error impacted my week adversely would be an understatement.
Here is a corrected list:
85-86: ~90 ohms (coil)
87-87A: infinite (can't touch)
87-30: infinite
30-87A: 0 ohms
In addition to this error, I think the guy who wrote the Japanese manual also wrote the English version.
To say this error impacted my week adversely would be an understatement.
Sorry to hear that. Wrong technical information is worse than having no information I think.
I wrote out a lengthy analysis of the system. I may find mistakes later, but I am taking a break now.
It appears I can remove the ECM from the starting system just by jumping the BY and BW wires at the starting relay. Unless I'm missing something, this should allow normal starting with the key, without harming anything at all. I will keep looking at it. I would still have to use the manual shut-off to stop the engine if the ECM won't do it.
The shut-off relay can be bypassed by jumping the W and RW wires, though, so using the key to shut the mower off is possible.
The key won't give the relays too much juice and damage them. It supplies the relays with juice when the ECM is working, so the relays shouldn't know the difference.
If I am right about this, doing it would be very easy. I could even do it temporarily without cutting into anything.
I am not planning to do it, but it's something to think about if the ECM turns out to be bad. I think it would be pretty simple to add a couple of safety switches (PTO and motion levers) back in if I wanted. I have no warranty to worry about, and the ECM may be unavailable if I need one 15 years from now.
The brake safety seems stupid to me. I see why a seat switch makes sense on a machine with nothing between me and the front of it, but I am supposed to be using the seat belt anyway. The motion lever switches seem like a good idea. I'm not sure what purpose the PTO switch serves except to prevent me from being startled because the blades try to move when I turn the key. Maybe someone here can tell me. Maybe it would harm the mower to start it with the PTO engaged.
The only other thing I know of that the ECM does is keeping the shut-off solenoid going for around 10 seconds, but I honestly believe I can handle that myself, or I can do some research and make a circuit that will do it for $15 instead of $340.
It appears I can remove the ECM from the starting system just by jumping the BY and BW wires at the starting relay. Unless I'm missing something, this should allow normal starting with the key, without harming anything at all. I will keep looking at it. I would still have to use the manual shut-off to stop the engine if the ECM won't do it.
The shut-off relay can be bypassed by jumping the W and RW wires, though, so using the key to shut the mower off is possible.
The key won't give the relays too much juice and damage them. It supplies the relays with juice when the ECM is working, so the relays shouldn't know the difference.
If I am right about this, doing it would be very easy. I could even do it temporarily without cutting into anything.
I am not planning to do it, but it's something to think about if the ECM turns out to be bad. I think it would be pretty simple to add a couple of safety switches (PTO and motion levers) back in if I wanted. I have no warranty to worry about, and the ECM may be unavailable if I need one 15 years from now.
The brake safety seems stupid to me. I see why a seat switch makes sense on a machine with nothing between me and the front of it, but I am supposed to be using the seat belt anyway. The motion lever switches seem like a good idea. I'm not sure what purpose the PTO switch serves except to prevent me from being startled because the blades try to move when I turn the key. Maybe someone here can tell me. Maybe it would harm the mower to start it with the PTO engaged.
The only other thing I know of that the ECM does is keeping the shut-off solenoid going for around 10 seconds, but I honestly believe I can handle that myself, or I can do some research and make a circuit that will do it for $15 instead of $340.
So the engine is stopped the same way with powering the stop solenoid?
The PTO switch is for safety aspect and probably also to prevent strain on the starter motor and battery. The added inertia of the deck blades would mean much longer time to accelerate the crank shaft leading to significantly higher currents and power losses.
The PTO switch is for safety aspect and probably also to prevent strain on the starter motor and battery. The added inertia of the deck blades would mean much longer time to accelerate the crank shaft leading to significantly higher currents and power losses.
The stop solenoid cuts the fuel. The ECM makes sure the stop solenoid is on for a while so the motor dies.
If you want to replace the controller you would require a timer that is active when you switch off the "ignition".
The tricky bit here is that this timer has to be powered while ignition 15 is off. So the timer has to be powered directly from the battery. Hence you want one that has a tiny inactive current not to drain your battery.
I had built my own controller and added LEDs for indication of switches. This makes trouble shooting so much easier. A pity Kubota did not add this in their original design.
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I am doing the unthinkable: reading the owner's manual.
It turns out the seat switch is okay. It will not shut the mower down if the PTO is disengaged. Not every machine is like that. I may hook it back up.
It will allow the mower to run over you, but it will not let it julienne you.
Not sure why the first owner unhooked it. He also removed the pulley guards, so he could get off the mower while the blades were moving, with nothing between him and the belts and pulleys except shoes.
It turns out the seat switch is okay. It will not shut the mower down if the PTO is disengaged. Not every machine is like that. I may hook it back up.
It will allow the mower to run over you, but it will not let it julienne you.
Not sure why the first owner unhooked it. He also removed the pulley guards, so he could get off the mower while the blades were moving, with nothing between him and the belts and pulleys except shoes.
I am not sure why they built the ECM. It seems like a bunch of analog stuff plus a simple timer would have been cheaper and easier to fix.
On the other hand, they design and build mowers, and I can't even get one running.
Well, that's what they did. They built a timer and added some safety switch logic. Production cost maybe $30 in quantities, $340 sales price, looks like a good business model to me.
Russell King
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Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
I think Kubota engineers (all engineers really) use systems that are similar across the product lines.
On tractors they don’t want to allow the engine to crank if the PTO is engaged. They also don’t normally allow the operator to get off the seat if the PTO is engaged. That is safer for modern civilization.
I think they just follow that same logic on all equipment like your mower.
On tractors they don’t want to allow the engine to crank if the PTO is engaged. They also don’t normally allow the operator to get off the seat if the PTO is engaged. That is safer for modern civilization.
I think they just follow that same logic on all equipment like your mower.
I see what you're saying. It's easy to get power to run a solenoid when the mower is running and you don't care about using too much because the system is charging, but you can't set up a kill switch so it draws power all week after you get off the mower.
Pushing the lever on the engine is not exactly hard. It's exposed on the right side. Gets hot, though.
Don't forget the cost of putting it in a hard case that can't be opened for repairs.Well, that's what they did. They built a timer and added some safety switch logic. Production cost maybe $30 in quantities, $340 sales price, looks like a good business model to me.
I know, I believe that is included in my cost calculation.
But, in fairness, I think the potting was done to improve reliability because of vibrations. So I do not believe the potting was done to prevent you from repairing it.