Won't start occasionally get starter engagement sound

[Texasmark]

It was a bad ground connection - removed the old ground cable, wirebrushed the area, then replaced the ground cable and bolt with new stuff and everything is great now.

Good. I just re-read my post and realized that after I said to remove the connections I forgot to say "shine them up" before reinstalling them.

 

[Redneck in training]

I have a JD 990 (made by yanmar) and just today I've had an issue with it failing to start. Never had a problem before today. When it starts it starts fine - immediately fires up. When it doesn't start, I'll first get a little clunk like the starter engaged and then nothing - no cranking. On subsequent attempts I get nothing at all. Battery is fully charged - at 12.9V. I get the fuel gauge coming on when I turn the key. When I'm not getting anything (no clunk) I can't run the intake heater either with is interesting. When I do get the clunk I am able to run it. Seems like a starter problem but could be some safety interlock circuit failing too. Neither should stop me from running the intake heater. Tried hitting the starter with a mallet to see if it could be persuaded. Any ideas?

Check seat switch or bypass it. If it doesn't help then check the other interlocks such as "in neutral", brake etc

 

[Wagtail]

It was a bad ground connection - removed the old ground cable, wirebrushed the area, then replaced the ground cable and bolt with new stuff and everything is great now.

Good stuff. :thumbsup:

Apologise for miss-reading your OP.