96 GC Rear Wiper Problems

I replaced my seized rear wiper motor about 6 weeks ago and everything was working fine. Now it seems to have a mind of it's own and turns on by itself when the switch is off. Then it stops for a few minutes and then it starts again. When it does stop, my switch sometimes works and then it doesn't. Even when I turn off the ignition it continues to run. I have to open the back hatch to get it to stop. Anybody have any clues or suggestions before I take it to a shop and get the runaround of somebody chasing my electrical system.

check the Switch prolly a broken wire going to the switch.

Was the new motor mounted with the motor in park position? If not it will be fooled into trying to park and continue this. Take the arm off and start the wipe, shut it off to see if the problem continues. If not, put the arm back on, it is now in the park position.