Step 1. buy a decent multimeter $50 is Ok. you can learn at good rate of speed, better that almost anything else! than having a top electronics tech teach (and they can't cause there earning $100,000+) walk you through a circuit check process. Youtube in 2016 is now one of the best learning tools available, as good if not better than many Tech schools.... I have visited! Really, The fact is YOU can learn as much as YOU want as fast as YOU want by just doing, reading and watching Youtube! and practicing...Read, about the Engineering of window circuits, switches, wiring, motors and schematics...If you really do / did this in 6 months time you will know as much if not more than 95% of what "shops" know on electrical. Regards