Replaced Ignition Switch now blades engage but won't disengage

[StarTech]

Don't believe you problem is ignition switch related, as the PTO switch should be the disconnect for the clutch unless you have a RIO and the key switch is the wrong one and is backfeeding the clutch.

Just how do explain a back feeding of the PTO clutch from the ignition switch?

The only for clutch to receive power is via the PTO switch [which is an on/off switch] via the ignition switch.

As mention it can be a clutch failure to disengage even though its power source is removed. This is why some mowers has a damper diode in the PTO circuit.

 

[bentrim]

Just how do explain a back feeding of the PTO clutch from the ignition switch?
View attachment 71970
The only for clutch to receive power is via the PTO switch [which is an on/off switch] via the ignition switch.

As mention it can be a clutch failure to disengage even though its power source is removed. This is why some mowers has a damper diode in the PTO circuit.

Without a RIO that should not be possible IF the correct switch is installed. But it the mower has RIO,which according to the diagram it does not, that again should not be possible but I have seen electric do strange things. Best to take a volt reading on the clutch wire to be sure it is no voltage in it. Then one would assume the clutch is damaged or a bearing is bad. I once condemed a JD 345 for a locked engine only to find the clutch bearing had locked up. Doh!
According to the OEM trining I have recieved the diode is to kill excessive voltage spike from the clutch when it is shut off. It sends it to ground instead of back thru the wiring where it was destroying switches. Just as with any coil a voltage spike is caused when a coil is turned off. Years ago I got a jolt from a 12 volt relay, touching the wrong terminal when it was turned off.

 

[StarTech]

Relays can go into self cycling if the diode is not there.

Here one of my stupid mistakes for you. While working a linear amp, I drained the power supply caps. While the unit was still unplugged they recharge themselves because whoever built the amp didn't install the bleeders. It took off part of my finger tip with a 3rd degree burn. Ever since I make those bleeders are there and if not install them.

When the owner brought in the amp, he said it was a 500 watts unit. When it left the shop it was peaking over 1500 watts. I actually burn up my mini RG8 800 watt cable and had to replace it.