This weekend I cleaned the battery terminals on our small diesel tractor (they had some corrosion) and now it won’t start without a boost. There was not enough corrosion that I think it could be a contact issue, nothing visibly seems wrong, no issues at all with tractor prior to this. It is fairly new and hasn’t had a ton of use. Help! 
Did you fully tighten the connections back? Like, wiggled them and they didn’t budge?
What, if any, sound happened when you turned the key? If absolutely nothing, make sure those connections are tight. If still nothing, then the batter is dead. If a “wah wah wah” noise of the engine trying to turn over, check the connections again.
In putting things back, and not fully tightening things, it could have created enough of a short to drain the battery.
You can try to jump it - car or truck. If still nothing, take it to Advanced Auto or somewhere similar, ask them to check the health of the battery, and put a full charge on it
They are definitely tight cannot wiggle at all. I jump started it and ran it for about half an hour doing chores, shut it off and then immediately it won’t start again. Just a clicking noise
You may have bad battery cables. We had one which prevented tractor from starting. Changed one cable and it roared to life. Other issue might be tractor starter may be grounding out, but that usually gets you nothing when you crank the key.
This is not a Kubota is it? We have one with a worn plastic part connected to the slow/fast shift lever. If you slightly lift the white part up in front, tractor starts right up! We call it the anti-theft device!! Tractor has been starting like this 10 years or so. I figure replacing the plastic piece at the dealer will be at least $100. And the new plastic will just get worn like the one in place npw. I will just save my money! Ha ha
Other idea is if you have FULLY pushed in the turn-off button? If it is out the tiniest bit, those diesels won’t do anything! No crank at all.
Hope one of these ideas is helpful.
Stupid question, What do you mean turn off button?
Not a kubota, john deere. My first tractor and diesel vehicle of any kind so I’m a bit lost lol
My Kubotas have a knob/button that you pull to shut the tractor off. Knob comes out about 3-4 inches, engine stops. Same pull out knob set-up to shut off with the Kioti (though Dealer says Kioti tractors ALL shut off by turning the key. Ha ha) and my friend’s JD tractor. Then you push the knob back all the way back in. If knob is not all the way back in, the tractor will just crank with the key turned, not start.
If battery is not bad, do check the battery cables. We had a similar issue earlier this summer. Fixed with the cable change, cable had a short in it.
This learning by doing is a pain! Glad husband likes to tinker, works out the problem… eventually. I have very little patience with non-working machinery.
