Electrical issue with Z860a

[Rockfootball47]

My father-in-law has a 2009 JD Z860A zero turn and is having issues with starting it. This all started last year when he was installing a new battery in it and the colored protective caps on the battery leads were reversed. This led him to installing the battery backwards and attempting to start it. I believe that he heard a grinding noise when he tried to start it and released the key immediately. After this happened when he tries to start it cranks but will not turn over on its own. He has only been able to start it by "jumping" the mower with his tractor. Once it's started he has no problem running it at all until he tries to start it again. He has confirmed that the battery is not the issue and is fully charged. He's wondering if there could be a fusible link that might be partially broken and will only work when there is extra "juice" running through it. Note that this mower has extremely low hours on it for its age, maybe a couple hundred.

Thank you for your help!

 

[jaxs]

My father-in-law has a 2009 JD Z860A zero turn and is having issues with starting it. This all started last year when he was installing a new battery in it and the colored protective caps on the battery leads were reversed. This led him to installing the battery backwards and attempting to start it. I believe that he heard a grinding noise when he tried to start it and released the key immediately. After this happened when he tries to start it cranks but will not turn over on its own. He has only been able to start it by "jumping"[/COLOR] the mower with his tractor. Once it's started he has no problem running it at all until he tries to start it again. He has confirmed that the battery is not the issue and is fully charged. He's wondering if there could be a fusible link that might be partially broken and will only work when there is extra "juice" running through it. Note that this mower has extremely low hours on it for its age, maybe a couple hundred.

Thank you for your help!

There's multiple reasons this will be difficult to solve so let's try and eliminate a few of those reasons. These parts of your post is confusing.
Crank and turn over are used inerchangably to mean starter turning engine over when key is held at start or start button is pressed. Start mean's that engine begin's to run when it's cranked. Clearify the red highlights above. When he "jumps",is he connecting cables to mower and tractor battery posts or is he connecting cable to starter on mower? Last but most important,we should be talking directly to whoever is testing and wrenching. Is that you or your fil? Do's that person know how to use all functions of a multimeter? I think this will help you get more responses.

 

[Rockfootball47]

Sorry for the confusion. By crank I mean't the starter would turn, but the engine would not turn over on its own or run. No sputtering, speeding up or slowing down of the "cranking". Just spinning of the starter. Similar to an engine without fuel being supplied or without power to the coil. When he jumps it he is connecting two jumper cables from the running tractor battery to the mower battery.

He is actually loaning me the mower for the foreseeable future due to me having 4 acres to mow which I have most recently completed with a 42" riding lawn mower....ugh, and since I have some engine experience I was hoping to be able to work on it and fix it without sending it to the dealer. I also do have access and experience with a multimeter for diagnosing issues.

Not trying to muddy the water anymore, but I do have some potentially helpful new information from this weekend. When attempting to start it to bring it to my house this weekend nothing seemed to be working like it had in the past for him (starting on its own like normal/jumping from the tractor). Note that it had been sitting for about 6 months since the last time he mowed. After two hours of attempts and on a last ditch effort he decided to attempt to run a jump lead from the mower positive battery terminal to the positive post on the starter solenoid and it started immediately. Once he got it up to my house we installed a new battery and tried to start it, and of course it started just like normal on the first try(no lead to the solenoid) and he said the trouble code was not showing up on the digital readout anymore. Note that this is the first he has mentioned the code to me. Dumbfounded by this he decided to try and start it later that same day to see if the issue was gone. Of course it would not start that time when attempting the normal start method.

 

[jaxs]

It was sounding like a bad battery that was replaced,then came the part about not starting again. Intermittent problems are the most difficult to handle. Hopefully you will get more responses now that it's clear what happened.