Windshield wipers and other accessories are not working

I have a LTS, five speed, with power windows and sunroof. My windows will not work, will not blow air whether if I have the A/C on or heat on, and my windshield wipers will not work as well. But, if I turn the A/C on, I can hear the compressor kick in. None of it makes sense to me, and I am a mechanic myself, but cannot figure out what it could be. I would like to get other's opinions before I buy those parts to see if that fixes it. I tried running a hot wire to both the windshield wipers and the blower motor, and nothing. One day, it did that to me, and I had left the negative battery clamp off overnight, and it started working again. Stayed that way till summer, and it did it again and will not work again no matter what I do.