ZG124E Ignition Problems

[gdskeese]

Howdy,

Neighbor has a ZG124E we can not get started. We seem to be chasing a gremlin in the electrical system. It started last year and we troubleshot it down to the parking break switch. After replacing it the mower ran great and started every time.
Fast Forward to now. Sitting in the seat and turning the ignition switch I can hear relays clicking and 12 volts are sent to the solenoid. The battery is full charged and there are twelve volts to the battery terminal of the solenoid. I tried what seems to be the usual fix of pulling up on the brake handle while holding the key to start.
Here is the list of parts replaced up till now.
1. Solenoid
2. Brake switch
3. Ignition switch

Items checked.
1. All fuses
2. Battery voltage
3. Voltage to solenoid (with key is START position)
4. Relays cycle when the handles are moved in and out

I am at a loss. Our thoughts are a possible defective seat switch.

Thanks for the assistance

 

[Dave_eng]

Howdy,

Neighbor has a ZG124E we can not get started. We seem to be chasing a gremlin in the electrical system. It started last year and we troubleshot it down to the parking break switch. After replacing it the mower ran great and started every time.
Fast Forward to now. Sitting in the seat and turning the ignition switch I can hear relays clicking and 12 volts are sent to the solenoid. The battery is full charged and there are twelve volts to the battery terminal of the solenoid. I tried what seems to be the usual fix of pulling up on the brake handle while holding the key to start.
Here is the list of parts replaced up till now.
1. Solenoid
2. Brake switch
3. Ignition switch

Items checked.
1. All fuses
2. Battery voltage
3. Voltage to solenoid (with key is START position)
4. Relays cycle when the handles are moved in and out

I am at a loss. Our thoughts are a possible defective seat switch.

Thanks for the assistance

Can you please clarify the problem. does the engine turn over and not start or not turn over. I am going to assume not turn over.

On the starter solenoid there is one smaller wire which is the signal for the starter to engage.

Get an inexpensive test light available at most auto parts stores. $10.

Connect the alligator clip to battery ground and then the pointed end to be held against the terminal on the solenoid where the small wire is connected.

When you turn the key switch to start, if all the safety switches are happy, your test light should glow.

Do that test and report back. Changing parts with the hope you will find the problem is always expensive and rarely successful.

Post pictures of your battery and its cables.

Post pictures of your starter.

Trace the battery ground cable and photo where it is connected to the tractor frame or engine block.

You can get a lot of help on this forum but you have yo be prepared to do the tests and post photos asked of you.

Dave

 

[rentthis]

Check voltage to the starter (big wire) and see if it drops off while cranking. It might just be a bad battery or battery cable connections at the battery or frame. If you get 12 good volts to the solenoid and the starter and it won't turn over, you have a starter problem.

 

[gdskeese]

Thanks for the information to this point. I am pulling my hair out with this project! Here is a more detailed list of our troubleshooting up to now.

1. Last year we changed the brake switch. The connection wiggled loose and the switch would not make contact every time.
2. Replaced the starter solenoid. It had 12v from battery and 12v to both small terminals. it would not engage the starter unless you jumpered across the two top posts. New solenoid from Autozone fixed that problem.
3. Replaced worn ignition switch. It was losing contact with even the slightest bump of the key.
Mower ran great all summer. We had a cold snap of three days below 25 degrees. Now it will not engage the starter. I replaced the battery with a known good one that we bought for his other mower. This did not change the mower's response.
Here are the steps I took tonight.
1. Verified the battery voltage to be 12v at:
Battery - good
Solenoid to battery - good
Solenoid to starter - NOT GOOD (no voltage) This was tested with the key placed in the start position, brake set, control arms out, PTO switch disengaged and seat switch actuated.
Two small terminals at base of solenoid - 12v at both when key is turned to START position
2. Checked the operation of the seat switch by measuring for continuity. Outside posts showed continuity when switch is pressed in. Inside post show continuity when switch is pressed in. Reconnected switch and measured voltages. 12v present at the switch.
3. Cycled the brake handle while holding the key in the start position. No change in behavior.
4. Solenoid indicated 12v at the battery wire always, 12v at the two small terminals when the key was placed to START. No voltage from solenoid to the starter.
5. Numerous relays make clicking sound as I cycle each of the arms and place the key to start.
I included the requested photos.
Thanks again for the help.
Gary

 

[gdskeese]

I submitted a detailed write up last week and the site said it had to be approved by an administrator. Does anyone know how to contact an admin so the post can be approved?

Thanks

 

[eserv]

Can you please clarify the problem. does the engine turn over and not start or not turn over. I am going to assume not turn over.

On the starter solenoid there is one smaller wire which is the signal for the starter to engage.

Get an inexpensive test light available at most auto parts stores. $10.

Connect the alligator clip to battery ground and then the pointed end to be held against the terminal on the solenoid where the small wire is connected.

When you turn the key switch to start, if all the safety switches are happy, your test light should glow.

Do that test and report back. Changing parts with the hope you will find the problem is always expensive and rarely successful.

Post pictures of your battery and its cables.

Post pictures of your starter.

Trace the battery ground cable and photo where it is connected to the tractor frame or engine block.

You can get a lot of help on this forum but you have yo be prepared to do the tests and post photos asked of you.

Dave

fairly simple wiring diagram

 

[coachgeo]

I submitted a detailed write up last week and the site said it had to be approved by an administrator. Does anyone know how to contact an admin so the post can be approved?

Thanks

My bad.... just now saw that a post was awaiting approval. Done. Thanks for your help toward solving this fellows issues.

 

[lugbolt]

It's likely the brake switch again. The system works weird. With all the switches in "neutral", +12v is allowed to flow to the starter solenoid; but ground to the solenoid is switched by the brake switch. The brake switch is a known failure point on the older Z100's.

Tell your neighbor to call a Kubota dealer and ask him to do the Kommander confidence campaign. Most Kubota owners either got or will get a letter referencing this. It'll solve the brake switch issue, and they'll also address SEVERAL other issues, free of charge, including transportation.

Trust me, you can't beat this free fix. I've done a couple of them so far and it's pretty involved and is a permanent fix for the brake switch repeat failure, potential deck belt coming off, etc. Be forewarned, some dealers don't like to do them because of the time it takes. Find another dealer. It's stupid to not like them, as Kubota pays the dealer pretty good to do it. Even if it's out of warranty, Kubota will pay for this campaign to be done. Ask the dealer to look up the serial number and they'll find out what gets done and what doesn't. The bulletin actually has 5 or 6 repairs that can be done if they've never been done in the past, most are preventive-but WELL worth getting done! Those mowers are really sweet, but they seemed to have a couple issues-and Kubota is stepping up to the plate to fix them. But the way I understand it, this program only lasts so long. And don't wait until the middle of mowing season to do it.

The brake switch itself has been replaced with a new style switch, which also involves replacement of the crossmember that it's attached to.

 

[100 td]

Sounds like a big win if he can get the campaign happening lugbolt!

 

[Dave_eng]

eserv
Do you have a WSM for this machine.

I have spent over and hour drawing colored lines on the wiring diagram trying to understand the circuit.

The brake light switch has two independent circuits it is controlling, the seat switch the same.

If there is a trouble shooting section in the WSM, it would make life easier.

I note there are two fly back diodes. I have marked them #1 and #2 in this diagram.

#1 is in series with the starter solenoid. If it is blown, no power gets to the solenoid.

The diodes may look like this one.

Since the owner has a multimeter, locating the diodes and doing a simple test for continuity in one direction and no continuity with polarity of multimeter leads changed.

If this machine does have a campaign, then getting it done makes more sense than all of us trying to figure the system out.

Dave

 

[Dave_eng]

Thanks to another forum member, I have a lot more info to share.

The ZG electrical systems are complicated and as I said previously, getting the brake switch campaign done immediately makes the most sense as it very well could solve your problem.

The simple No crank diagnostic chart

I know you are looking for a simple answer to end your frustration, but unless you are very experienced in tracing the logic of the Start system and Operation presence system, you will just go crazy.

Any more questions?

Dave

 

[gdskeese]

Thank you to everyone for the great advice. This thing has caused me to get a lot bigger bald spot! The electrical system has put me through some crazy twists and turns.

I am going to push for him to get it to the dealer for the campaign fixes. I will let everyone know the fix when he gets it back (in about 6 weeks with our local dealer).

Gary

 

[eserv]

Thank you to everyone for the great advice. This thing has caused me to get a lot bigger bald spot! The electrical system has put me through some crazy twists and turns.

I am going to push for him to get it to the dealer for the campaign fixes. I will let everyone know the fix when he gets it back (in about 6 weeks with our local dealer).

Gary

Warranty on this campaign is until January 9 2021 so there shouldn't be any question of them doing it!

 

[lugbolt]

Warranty on this campaign is until January 9 2021 so there shouldn't be any question of them doing it!

Absolutely!

The campaign, on some of the mowers, is quite involved. In particular, there are actually multiple fixes encompassed within the same deal. If you are a Z100 or ZG100 series owner and reading this, NOW is the chance to get over on Kubota. They're spending a LOT of money fixing these things, and it's temporary as eserv mentioned, so get it done while you can. And honestly, since the grass ain't growing right now and dealers are usually slow, now is going to be the best time to get it done before the dealers start getting swamped with spring and summer repair jobs.

Especially the brake switch deal. If you still have the original brake switch, it will fail eventually. It's not "if"; it's when and usually it's always at the worst possible time...right in the middle of a mowing, just before dark, before a big event. In other words, there's no excuse to wait. Get it done ASAP.

 

[gdskeese]

Good evening everyone,

Update on the ZG124E. Neighbor took it back to the dealer today and they are looking into the problems. Hope to hear something in the next couple days. Our bets are on the brake switch.

Thanks again for the help.

 

[leiterch]

Just typed a long reply and lost it. Here goes again.

I am having a similar but different issue. Mine is happening after I run the mower for a short amount of time. The issue is Icant Crank the engine with the key. I can however jump the engine direct, but it won’t run. I have bypassed the safety switches to eliminate those from the equation and still won’t stay running. If I let the mower sit it does eventually start running. I have no audible click at the relays. I do have power at the starter and like I said it will turn over if I jump direct at the starter. Not sure why it would run for awhile then just quit and die on me. It’s weird. Any help would be great.

 

[lugbolt]

you can't just bypass the switches on this mower it don't work that way. Look at your switches. There are 4 terminals on the switch not two, so you can't just wire around it and expect them to work properly.

at least two of the switches on the ZG100 series (and Z100 and Z200 series) are no/nc switches. So while one set of contacts are normally open, the other set it normally closed. When you push the plunger in, one set opens and the other closes.

The WSM shows how they work and that WSM and some thought is all that's needed to diagnose one of these mowers.

 

[leiterch]

you can't just bypass the switches on this mower it don't work that way. Look at your switches. There are 4 terminals on the switch not two, so you can't just wire around it and expect them to work properly.

at least two of the switches on the ZG100 series (and Z100 and Z200 series) are no/nc switches. So while one set of contacts are normally open, the other set it normally closed. When you push the plunger in, one set opens and the other closes.

The WSM shows how they work and that WSM and some thought is all that's needed to diagnose one of these mowers.

Thanks for the reply. What is weird is I actually found the problem finally today. I had a broken wire at the battery. So it was making intermittent contact on the smaller gauge wire. I still have the seat and brake bypassed and it worked great. As soon as I found the problem with the broken wire and fixed it, I heard the relays click and then I gave her a go and mowed for a couple hours. I will hook the safety switches back up later before I head back out again. I don’t know how or why it worked, but jumping the switches worked for both the seat and the brake. ???