ZD326 starter problems

[Earl W]

Having challenges getting the beast to crank/turn over when cold. If I am lucky, every once in a while it will turn over when hot, but not often. I have read the threads I can find but have been unable to solve the issue.

The battery new and good with clean terminals, it turns over and starts every time using a remote starter switch between the hot wire on the starter and the starter solenoid.

The interlocks are all working and to make extra sure, every time park it, I make sure I can get out of the seat without it cutting off and it cuts fine when I am in the seat so the seat interlock is working.

I have pulled inspected and re-inserted all of the small spade fuses.

So far, replaced the battery, battery ground wire, starter, starter relay and the 50 amp fuse.

After replacing the battery and starter, had no issues for about a month, then the issues started again.

My typical process is to give the glow plugs about 10 seconds, then move the switch to the cranking position. When I do that, I get 10.8 volts on the meter at the starter solinoid, not the full 12+ I would see off the battery or when I am using the remote starter cable which always works. You can also see the needle drop on the fuel gauge when the glow plugs have power and go down further when you try and engage the starter, which suggests both the glow plugs and starter are drawing power depending on the switch position. I have also tried going direct to the cranking position on the switch, but that does not work either.

All that made me wonder if the glow plugs are drawing enough current to prevent the starter solenoid from making contact. With my Kubota tractor, you wait until the glow plug light has gone out before you crank, so I believe the glow plugs are not powered when you are cranking. But I do not see a temperature sensor in the ZD electrical diagram for that feature and the glow plug light does not go out when you are cranking making me think they stay on. Also I have tried using the remote starter cable with glow plugs active and it cranks and starts fine.

Running out of ideas other then making the remote starter cable a permanent feature.

Suggestions?

thanks Earl

 

[Captain13]

Maybe the start switch. Check the voltage at the input to the switch. You know the output is 10.8 at the solenoid but check it at the switch when you check the input voltage. You are dropping about 2 volts somewhere. Could be across the switch. Also check you frame grounds.

 

[rjcorazza]

I had similar problems with both my ZD326 and ZD331. I installed a relay that provides power to the starter solenoid directly from the battery, avoiding the potential of low voltage on the starter switch wire. There can be resistance on the blue starter wire as a result of many things, including the various OPC switches.

I also installed a Kubota heat shield over the starter that is made for the newer zd1211 mowers. It's plug and play on the 331, but I believe you would have to drill mounting holes on the frame for the 326. (Haven't installed the heat shield on the 326 yet. Finally, when I was dealing with all this several years ago, I found I could buy just the solenoid on eBay for about $20. They seem to last about 600 hours or so, and take like 15 minutes to swap out.
This photo shows the relay setup, someone here, or on another forum kindly posted this several years ago. I don't know who to thank, but it was very helpful.

 

[Earl W]

Thanks, I can check the switch after the Hurricane blows past.

Frame ground is good, tested when I replaced the battery ground cable and retested it as part of the debugging process.

I had similar problems with both my ZD326 and ZD331. I installed a relay that provides power to the starter solenoid directly from the battery, avoiding the potential of low voltage on the starter switch wire. There can be resistance on the blue starter wire as a result of many things, including the various OPC switches.

I also installed a Kubota heat shield over the starter that is made for the newer zd1211 mowers. It's plug and play on the 331, but I believe you would have to drill mounting holes on the frame for the 326. (Haven't installed the heat shield on the 326 yet. Finally, when I was dealing with all this several years ago, I found I could buy just the solenoid on eBay for about $20. They seem to last about 600 hours or so, and take like 15 minutes to swap out.
This photo shows the relay setup, someone here, or on another forum kindly posted this several years ago. I don't know who to thank, but it was very helpful.
View attachment 46834 View attachment 46836

Thanks! I was afraid I might have to get a starter assist relay. The heat shield makes sense, I had never considered it and these mowers tend to run a lot hotter then my L3010.

And I like your helper in the picture

 

[lugbolt]

if you need the starter relay kit, it's just about as easy to order it from Deere, part number AM107421. I keep them in stock, yeah, at a kubota dealer. Kubota has a kit too but it's like $100 or so, and is almost identical. Deere kit is a little under $40. I have made them in the past, like in the diagram. By time you make it with the correct connectors, wire, relay, socket--you're close to what the Deere kit costs. A couple bucks less. At the time I had $29 tied up in parts plug a bunch of aggravation running around trying to find any place that had the correct socket, relay, and connectors....and the Deere kit was $33.60 with tax

A lot of times folks will use a volt meter set to ohms & check for "good continuity" between, say, ground and the ground wire. Well, you will get 0.0 ohm if ONE strand of wire is making connection, but when you put a load on it, things happen differently. That's why I test differently; and Kubota doesn't tell you about it either in the WSM.

At one time there was a bulletin that addressed one of the diesel zero turn's wiring (ground). I don't remember if it was the ZD3xx series or the older ZD21/ZD25/ZD28. But basically it amounted to the fact that the ground strap between the engine and chassis was placed incorrectly causing slow starting and eventually wiring damage due to "bad" ground. It wasn't "bad" but it wasn't a good ground. They either put a second ground strap on, or they re-routed the original to the frame instead of the engine mount. I can't remember but it's a good example. Grounds=important!