Toro Timecutter SS5000 - starter keeps running with key off

[Grunkle]

Hi, new to the forum.
My Toro is second-hand to me. The electronic brake controller failed along with the ignition solenoid, as it sat outside over the winter. (we moved recently, and shop was full)
I replaced the brake controller, solenoid, battery, and ignition switch. Now it will start and run, but starter still running after key switch is off. Fortunately I noticed this right away, as I was testing the new parts to make sure all was good.
I tried 2 other solenoids, so figure I ruled out a bad solenoid. (all were brand new)
I left small wires and battery wire on solenoid but removed wire to starter. Then connected starter wire to battery wire and motor started right away. When I disconnected starter wire from battery wire the starter stopped and motor kept running as it should. When I turned key off the motor shut off properly.
I'm considering simply installing a start button to make mower operable, but I'd sure like to find what the real problem is.
Anyone have an idea what's wrong?
Thank you!

 

[Auto Doc's]

Is it a worn starter Bendix gear causing the gear to hang in the flywheel teeth?

 

[Grunkle]

I didn't think of that! But...when I unhook the ground wire from the solenoid the starter shuts off and disengages the flywheel. There's still power to the starter until I unhook that ground wire. I've looked for faulty ground wires, but haven't found anything wrong yet.

 

[StarTech]

What ignition switch did you install?

 

[Auto Doc's]

Like StarTech said, what starter switch did you use, they are not all the same internally. There is no such thing as universal fit.

 

[Grunkle]

I ordered one for a Toro Timecutter SS5000. It's identical to the old one, and produced the same results...