Starter still says engaged!

[PKRWUD]

Okay, first of all, yes, you need to use the test light.

See, if disconnecting the push-on wire from the relay stops the starter from spinning on it's own, then the problem lies in the ignition switch circuit. It would mean that the switch was sticking in the start position. But, as you mentioned, the clutch switch would also have to be closed, but you said that that didn't effect it. That means it had to be a sticking relay. This is a lot like a cat chasing it's tail. Rather than run in circles, let's do this methodically.

Hook up the test light like I suggested, and do what I suggested. Tell me what happens.

Take care,
-Chris