No power on the pto

What's the make & model of your tractor? If this is a garden tractor, it sounds like either the belt on your (I assume) electric clutch is slipping or you have low power to the magnets. If this is a farm tractor, then your pto clutch plate is worn and/or needs replacement/adjustment.

Basically your PTO is an electro magnetic clutch....when power is applied (12 volts) from the battery, the magnet is energized and the two plates come together and you have then energized your PTO clutch and it should drive the V-belt....so If you disconnect the power to the magnet the magnet becomes denergized and the two plates move away from one another ,thus the v-belt stops turning .
It could be the switch,or more than likely it is a "relay" that has gone bad ,ie, the contacts on the relay have become pitted with use and stick when they get hot from use....thus when you disengage the PTO switch the relay stays in contact thus delivering power to your PTO clutch .....if you have a wiring diagram of your unit you should be able to find the "safety or PTO relay" again this is just my theory!
If you can use a meter,you could check for voltage on the PTO wire when you disengage the PTO switch,if power is still present then we know it's an electrical issue with the switch or relay ,OR some how power is back feeding down this wire that keeps the clutch energized????? Maybe two wires making contact ????
Unfortunately a good small engine mechanic may be the way to go on this repair ......most people have a clutch that won't engage !
I hope this sheds some light on your issue ,Jim

The light just indicates power is available for the PTO clutch. It doesn't it reaching the clutch. You need to unplug the PTO clutch and check to see if voltage is there. If it is there then clutch itself is bad or the wiring from the connector to clutch is broken. If no power at the connector then you have wiring problem and may even have part of the PTO switch not working.

i believe the lever is on the left side that operates the pto. on some models it will have a plate stating its the pto, you'll have to start the tractor, and engage the clutch, then engage the pto, and release the clutch. Others you simply engage the pto once you've started the tractor

On the front of the clutch, you should see 3 or 4 bolts with springs under them, they are the adjustment screws. Insert a .018" feeler gage between the clutch's plates and tighten the screws. You will have to go around to each screw several times as adjusting one effects the setting at the others.

If you have a test light you can check power at the connection to see if power is present. If power is present check your ground. Not sure if safty switch could kill power to the pto, but you can test pto by connecting 12v and a grond to the plug on pto with engine off to see if clutch is drawn in. You should see it move and hear a click.

belt worn causing too much travel of lever and rollers

roller and adjustment plate worn

spring tensioner on roller worn-missing

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

If you changed the belt make sure it did not interfere with the wire that runs from the pto clutch, sometimes that belt can rub on the wire and wear through it,also if you had the clutch off make sure you aligned the steel retainer bolt that sets in the alignment hole on the pto clutch,this keeps the clutch from spring when disengaged if you don't get that pin through the hole in clutch it can push on the clutch and bind it.Also it may be possible to plug that pto switch in backwards.Also if you jumped the fuse out it may now have burnt the switch or wiring somewhere.

It's likely that your clutch needs adjustment. To adjust, you just need to loosen the two screws on the plate and slide it a bit so the clutch better engages the rear dog clutch. Have you ever taken the tiller portion off the transmission to grease the clutch? If not, before adjusting it you might want to do that. It could be that the clutch isn't sliding back far enough to engage the rear end and a little grease is all it needs. This service requirement is explained in the owners manual for the tiller. One last point, the tiller must be in neutral when engaging the pto clutch. From your note, it sounded like you were engaging the clutch with the forward/reverse lever in the forward position. The lever must be in neutral when engaging the pto clutch.

Did you install the original electric clutch from the old engine?

If so, you may not have the adjustment right. On most electric clutches, there is a specific distance between the drive plate and the driven plate. Check your shop manual (if you have one) for this, as it does vary between manufacturers, and depending on the size of clutch.