89 chevy blazer

I am having a problem with my windshield wipers. I bought my 89 chevy blazer 6 years ago and about 4 years ago the wipers would come on when I would hit a bump, put on my turn signals, or the vibration from the music. Well the other morning I was getting off work and my windshield wipers were frozen to the windshield. I defrosted it but the windshield wipers would not go down. I turned them on and off and I eventually had to manually get them down. When I got home I popped the hood and turned on the wipers. They went up and stopped. I applied a little pressure and they kicked on but a noise was coming from under the hood. Due to the wipers coming on whenever they wanted to over the last four years, does it sound like the wiper motor has burned out or is slowly going out. And if so (minus labor of course) how much would a motor cost me. I appreciate your time. I kknow nothing about cars and I could use all the help I can get.
God bless you and thank you for your time
Atolocus