The Wiring - How Turn Signals Work | HowStuffWorks How Turn Signals Work. by Karim Nice. The Wiring. Prev NEXT . Let's take a look at how the turn-signal circuit is hooked up. The turn-signal circuit gets power when the ignition key is on. The power goes through a fuse panel into the thermal flasher. From there it goes to the stalk on the steering column. Related searches for blinker wiring diagram gm brake light blinker wiring diagramturn signal wiring diagramflasher wiring diagramgm wiring diagramsgm light switch wiring diagramgm wiring diagrams onlinegm truck wiring diagramgm wiring harness diagram