Kubota zd28 mower was running fine put away but now PTO wont engage.

If it acts like the blades are engaged, try tracing the wires to see where they are shorted out, start by disconnecting the wires from the switch. You may need a new switch

Check the linkage from lever to deck

ether switch bad fuse blown behind dash or pto bad if pto 300.00

could be a couple of things... fuse? switches? bad clutch?

You've checked the wiring to the PTO and it looks OK. Does the PTO engage when the switch is thrown? Do you have a multi meter , so you can trace the voltage to the switch, from the switch to the PTO. You also should check the safety switch (s) which will prevent the PTO from engaging if there is a faulty switch. And it could simply be a fuse that has blown.

I would start by having battery tested. If u remove it and take it to auto parts store they will test it for free. It could be that the battery will not hold a charge or your tractors alt. is not putting out a charge

Visit the on-line store, known as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem -

https://www.reliable-store.com/products/kubota-b2630-tractor-workshop-service-repair-manual

If you wired the pto directly to the battery and still kicks off and on, you have a bad pto clutch. They can be expensive but they are fairly easy to replace. Hope this helped.

I’m happy to assist further over the phone at https://www.6ya.com/expert/layne_0fccff498c319c32

unplug the clutch and see if it blows a new fuse if not pull the clutch off and check for bare wires that may have rubbed against metal

check the wires they rub on sharp edges