Z122R solenoid clicking but no start

brihvac

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Z122R zero turn solenoid clicking but no start

I have seen this asked a million times but no one ever follows up with the fix. It did it last year and just did it again today. The starter solenoid clicks (you can even feel it) but it seems like its not enough to pull it in to crank the engine. I pulled the 2 small wires off and when you turn the key to start you are getting 12.4v to the solenoid through the one wire. I was assuming the other wire was a ground but when I test continuity to ground it is not (issue?). NOW, I made a jumper set of wires for the solenoid and went directly to the battery and the solenoid works and it will crank. Hook the wires back up and you can feel, and hear, the solenoid clicking but no crank. If you move the parking brake, arms, get off the seat...The solenoid will not click so I am assuming those safety's are working. I did see on a YouTube video that a guy was having a similar problem and in the comments it said that he put a new PTO switch in and that was his issue. When I work my PTO I can hear it clicking. My next move is to hook the one wire that has the 12v (when key is turned) onto the solenoid and run a wire directly from the battery ground to the other terminal and just leave the other wire off and see what happens. I do not want to just start changing parts but this is driving me nuts because the solenoid is clicking but not enough to crank the engine. Just don't understand whats going on. I can not find a wiring diagram anywhere and even when I went to the dealer they had no kind of diagram whatsoever in their books.
 
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whitetiger

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Re: Z122R zero turn solenoid clicking but no start

I have seen this asked a million times but no one ever follows up with the fix. It did it last year and just did it again today. The starter solenoid clicks (you can even feel it) but it seems like its not enough to pull it in to crank the engine. I pulled the 2 small wires off and when you turn the key to start you are getting 12.4v to the solenoid through the one wire. I was assuming the other wire was a ground but when I test continuity to ground it is not (issue?). NOW, I made a jumper set of wires for the solenoid and went directly to the battery and the solenoid works and it will crank. Hook the wires back up and you can feel, and hear, the solenoid clicking but no crank. If you move the parking brake, arms, get off the seat...The solenoid will not click so I am assuming those safety's are working. I did see on a YouTube video that a guy was having a similar problem and in the comments it said that he put a new PTO switch in and that was his issue. When I work my PTO I can hear it clicking. My next move is to hook the one wire that has the 12v (when key is turned) onto the solenoid and run a wire directly from the battery ground to the other terminal and just leave the other wire off and see what happens. I do not want to just start changing parts but this is driving me nuts because the solenoid is clicking but not enough to crank the engine. Just don't understand whats going on. I can not find a wiring diagram anywhere and even when I went to the dealer they had no kind of diagram whatsoever in their books.
Here is the diagram from the WSM
 

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North Idaho Wolfman

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The second wire is an switched (by the solenoid) 12 volt wire to the run solenoid (fuel stop solenoid). leave it alone.

Some say they are not getting enough voltage or amperage to the starter to allow it to pull in hard enough to engage the contacts to power the starter.

The fix is to use the existing starter solenoid wire to power another relay, that relay sends power to the solenoid to make it work better.

Most of the time the real reason is a failing starter solenoid, and doing all that extra work will sometimes make it work for a while then it will fail. ;)
 
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brihvac

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Wilmington Delaware
The second wire is an switched (by the solenoid) 12 volt wire to the run solenoid (fuel stop solenoid). leave it alone.

Some say they are not getting enough voltage or amperage to the starter to allow it to pull in hard enough to engage the contacts to power the starter.

The fix is to use the existing starter solenoid wire to power another relay, that relay sends power to the solenoid to make it work better.

Most of the time the real reason is a failing starter solenoid, and doing all that extra work will sometimes make it work for a while then it will fail. ;)
I did order a new solenoid and when I pulled the old one I bench tested it and it worked so I figured it was good. But I do have a new one on the way.

Going back to the contact wires....Is one supposed to be a ground and the other 12v coming from the start switch? I am getting 12v on the one wire when I cycle the start switch. The other wire I thought was a ground BUT I have no continuity when I test the wire to ground. It has me confused because with a jumper direct to the battery the solenoid works. Seeing I have 12v on the one wire when cycling the start switch that is why I was going to run a direct ground to the other terminal and just leave the wire that was on there off and see what happens.
If any of my safety's were open would I have 12v going to the solenoid? I have it so I am assuming they are good.
 
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brihvac

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Re: Z122R zero turn solenoid clicking but no start

Here is the diagram from the WSM
Thank you. You know I went to the dealer to get this and they said none exist. I said so what does the tech do to trouble shoot? They had no answer for me. What is weird is it did it to me last year then it started working fine until today.
 

brihvac

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So I went out this morning and it clicked when I first turned the key like it was doing yesterday. Then I tried it again and it cranked and fired right up which is exactly what it did last year. So I wanted to see what was different from yesterday on my meter readings.
YesterdayOn the 2 small contact wires when I tested voltage across the 2 wires I got NO 12.4v. Individually one had 12.4v and the other had nothing.
Today Across the 2 wires I HAD 12.4v Individually they were the same.
That is telling me it has to be one of the safety's that was messing up because when it won't start there is no voltage between the 2 wires and when it starts I have voltage between the 2 wires
 

SDT

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Re: Z122R zero turn solenoid clicking but no start

I have seen this asked a million times but no one ever follows up with the fix. It did it last year and just did it again today. The starter solenoid clicks (you can even feel it) but it seems like its not enough to pull it in to crank the engine. I pulled the 2 small wires off and when you turn the key to start you are getting 12.4v to the solenoid through the one wire. I was assuming the other wire was a ground but when I test continuity to ground it is not (issue?). NOW, I made a jumper set of wires for the solenoid and went directly to the battery and the solenoid works and it will crank. Hook the wires back up and you can feel, and hear, the solenoid clicking but no crank. If you move the parking brake, arms, get off the seat...The solenoid will not click so I am assuming those safety's are working. I did see on a YouTube video that a guy was having a similar problem and in the comments it said that he put a new PTO switch in and that was his issue. When I work my PTO I can hear it clicking. My next move is to hook the one wire that has the 12v (when key is turned) onto the solenoid and run a wire directly from the battery ground to the other terminal and just leave the other wire off and see what happens. I do not want to just start changing parts but this is driving me nuts because the solenoid is clicking but not enough to crank the engine. Just don't understand whats going on. I can not find a wiring diagram anywhere and even when I went to the dealer they had no kind of diagram whatsoever in their books.
Just went through this with my 1993 B1750HSDT. The symptom was intermittent and infrequent so diagnosis was lengthy and difficult. I worked on it on and off for nearly a year.

Bottom line: Voltage drop across an aging key start switch allows enough current to flow to click the solenoid but not enough to reliably pull it in solidly to close the contacts to crank the engine. This produces the same symptoms as can a failing solenoid or starter, loose or dirty battery cable connections, failing battery cables, a failing battery or poor ground path between the battery and starter. This appears to be a common failure mode for Kubota machines that are several years old.

Because my symptoms were intermittent and infrequent, I changed all of the most likely candidates first, eliminating everything but the key switch and wiring harness (visually inspected) before getting to the key switch. As a result, this became an expensive repair as my B1750 now has a new starter and solenoid, 2 new Kubota battery cables, a new clutch interlock switch (it was functioning but sticky so I changed it anyway), a new battery (needed anyway), and a new Kubota key switch. Only the key switch was needed.

NIW's primary circuit relay option will solve this problem and for less cost than a new Kubota key switch but it is really simply masking the problem.

SDT
 

brihvac

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Wilmington Delaware
Re: Z122R zero turn solenoid clicking but no start

Just went through this with my 1993 B1750HSDT. The symptom was intermittent and infrequent so diagnosis was lengthy and difficult. I worked on it on and off for nearly a year.

Bottom line: Voltage drop across an aging key start switch allows enough current to flow to click the solenoid but not enough to reliably pull it in solidly to close the contacts to crank the engine. This produces the same symptoms as can a failing solenoid or starter, loose or dirty battery cable connections, failing battery cables, a failing battery or poor ground path between the battery and starter. This appears to be a common failure mode for Kubota machines that are several years old.

Because my symptoms were intermittent and infrequent, I changed all of the most likely candidates first, eliminating everything but the key switch and wiring harness (visually inspected) before getting to the key switch. As a result, this became an expensive repair as my B1750 now has a new starter and solenoid, 2 new Kubota battery cables, a new clutch interlock switch (it was functioning but sticky so I changed it anyway), a new battery (needed anyway), and a new Kubota key switch. Only the key switch was needed.

NIW's primary circuit relay option will solve this problem and for less cost than a new Kubota key switch but it is really simply masking the problem.

SDT
Mine is a 2015 with 77 hours on it. Original battery but it is doing exactly as you describe. I have a primary circuit relay that I think I will get ready so if it does it again I can try it. If it works I will buy a new key switch. Thank you
 

North Idaho Wolfman

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Thanks Whitetiger the wiring diagram gave the answer.

You more than likely have a bad starter relay! ;)
 

SDT

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Re: Z122R zero turn solenoid clicking but no start

Just went through this with my 1993 B1750HSDT. The symptom was intermittent and infrequent so diagnosis was lengthy and difficult. I worked on it on and off for nearly a year.

Bottom line: Voltage drop across an aging key start switch allows enough current to flow to click the solenoid but not enough to reliably pull it in solidly to close the contacts to crank the engine. This produces the same symptoms as can a failing solenoid or starter, loose or dirty battery cable connections, failing battery cables, a failing battery or poor ground path between the battery and starter. This appears to be a common failure mode for Kubota machines that are several years old.

Because my symptoms were intermittent and infrequent, I changed all of the most likely candidates first, eliminating everything but the key switch and wiring harness (visually inspected) before getting to the key switch. As a result, this became an expensive repair as my B1750 now has a new starter and solenoid, 2 new Kubota battery cables, a new clutch interlock switch (it was functioning but sticky so I changed it anyway), a new battery (needed anyway), and a new Kubota key switch. Only the key switch was needed.

NIW's primary circuit relay option will solve this problem and for less cost than a new Kubota key switch but it is really simply masking the problem.

SDT
Bumped this to provide new information.

Once again, it appears that the intermittent and infrequent no crank symptom displayed by my B1750 remains, and the new key switch did not solve the problem.

The only part of the cranking circuit that has not been changed is the wire in the wiring harness between the key switch and the solenoid, and this has been visually inspected twice. Everything looks good and there is no evidence of heat, loose or dirty connections or poor crimps.

For some reason, Kubota specifies a gasket between the starter and the engine, and I replaced it when I installed the new starter/solenoid. At the same time, I installed internal star washers between the heads of the starter mounting bolts and starter to assure good electrical connections between the bolt heads and starter.

Because of the lack of other possibilities, I now suspect a poor current path between the starter and the battery negative cable. The battery is positioned beside the seat on the right side of the transaxle on the B1750, and the negative battery cable connects to the transaxle rather than the engine. I next plan to install a new cable between the battery negative transaxle connection and one of the starter mounting bolts To eliminate this possibility.

Diagnosis has been difficult due to the infrequent and intermittent nature of the symptom, resulting in a parts changing scenario rather than a conclusive diagnosis.

Stranger things have happened, and I will post back with results.

SDT.
 

Daren Todd

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Re: Z122R zero turn solenoid clicking but no start

Delete. Realized it was bumped due to different issue
 

Palmettokat

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I don't see you testing the voltage while trying to crank it, if so missed it. If the voltage is dropping when trying to crank probably a bad connection on a terminal or inside a relay or starter. Or bad battery. Had that on my B2710 a week ago. Voltage on battery was good but dropped greatly when hit the key.

Had same action with a tractor few years back..inside of the battery cable clamps were glazed and had to ream them out to get ride of it. Starter solenoids at least my experience will click when they have issue.

If you have an amp meter the type that clamps around the wire you could check to see if starter is pulling real heavy load so most likely the starter in that case.
 

Davis DeWitt

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Z122rkw
Mar 13, 2022
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N FL
Ok so after exploring ALL of the previously discussed potential issues mine turned out to be the wiring harness adapter connecting to the PTO switch. The safety switch wire connector was broken and corroded and would sometimes make contact and other times not (only noticed because when removing the PTO switch to test part of the female wire connector on the harness end fell out) resulting in the unit thinking the PTO blades were engaged and prevent the cranking/starting or shut the mower off when the seat safety switch was not depressed.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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most common cause of this issue (clicks but don't start) is the brake switch.

Look at your wiring diagram, even the one above. One side of of the relay is energized when u turn the key. The other side has to be grounded somehow in order for it to actually "relay" like it's supposed to. The ground comes from the other switches, brake, neutral, etc. With that said you ideall would do a voltage drop test on the two wires at the relay. The hot side need to see less than 500mv drop, the ground side less than 500mv also. I bet, if you have no drop on the hot side, you'll find a large drop on the ground side...which would be due to a switch not switching.

The brake switch is a no/nc switch. Look at the diagram above. They are probably one of most common failed part on all of the Kommanders, and possibly on ALL of the Kubota mowers combined.

I am not saying it ain't some other issue, but the brake switch is usually the most common.
 

RiverFix

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Z121-skh-48
Aug 28, 2022
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Washington DC
most common cause of this issue (clicks but don't start) is the brake switch.

Look at your wiring diagram, even the one above. One side of of the relay is energized when u turn the key. The other side has to be grounded somehow in order for it to actually "relay" like it's supposed to. The ground comes from the other switches, brake, neutral, etc. With that said you ideall would do a voltage drop test on the two wires at the relay. The hot side need to see less than 500mv drop, the ground side less than 500mv also. I bet, if you have no drop on the hot side, you'll find a large drop on the ground side...which would be due to a switch not switching.

The brake switch is a no/nc switch. Look at the diagram above. They are probably one of most common failed part on all of the Kommanders, and possibly on ALL of the Kubota mowers combined.

I am not saying it ain't some other issue, but the brake switch is usually the most common.

Thanks for sharing the wiring diagram. Had the same problem with the "click" when trying to start. Discovered that the positive cable was loose at the starter which shorted it out and killed the solenoid as well. The positive cable got so hot it melted the rubber boot that covers the nut. Off to find a starter....
 

Poondaco

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Mostly Green Stuff
Jun 26, 2024
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Had the same problem. All the simple stuff has already been changed.
The hardest part to solve is the intermittent nature of the problem. Put on a new (insert whatever part you want) and it works long enough for you to run back to the computer to post a solution. Then everyone runs out and buys that part. Try to keep in mind, the reason folks are looking on forum is because they already tried the simple or obvious things, so posts suggesting stuff like "starter relay" are of no help to anyone at all and a major waste of precious time. Of course they already changed that. It was probably the first thing they changed.
Here is what I found: There is a wiring harness starting in the battery box area running very close to the engine all the way to the key switch area. The harness is enclosed in a black tubular wire loom with tape and zipties holding everything together. There are about 15 wires inside this harness. It is somewhat difficult to get this loom opened up due to all the tape and close quarters with the engine. There is a black ground wire inside which was melted from one end to the other. The wire runs from the battery area, through the harness all the way to the key switch area and terminates on the frame of the mower right below the right side directional control lever. The copper conductors of this wire were burned apart in multiple areas and would intermittently make continuity.
Not sure why this ground wire is needed, but the mower obviously was hunting for ground and the wire had lost good contact at the termination points. (corrosion, paint, loose, etc) I replaced this wire with new, adding anti oxidant to the terminations, and added two more grounds to frame for good measure. Be sure to inspect the other wires in the loom as they may have become damaged by the heat of this ground wire. Not sure if this is the solution for every single orange machine, but it looks to be a problem that will continue to present itself until remedied.
 

BellefonteBill

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Z251KH-254
Jun 30, 2024
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1
Bellefonte,PA
Hello,

I have a Z251KH-54 zero turn, and the starter will not crank when I turn the key.

This is not intermittent, the other day it did not restart while mowing. And hasn't started since.

The starter solenoid has 12v on the hot side and clicks but does not pass 12v to the starter.
The starter does crank when I jumper the solenoid to the starter with a jumper cable.
I was able to jump the starter and get it started bypassing the starter solenoid to get it back to the garage.

I installed a new starter solenoid and again it clicks but does not pass 12v to the starter.

You would think since it stayed started when I jumped the solenoid all the 'safety' switches are set.

I'm going to follow the comments above, but any suggestions on a plan of attack would be greatly appreciated.

Thank you
Bill


UPDATE: this issue was the parking break electrical connector had become loose, and did not satisfy all safety interlocks.
 
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