Mia gives an overview of how turn signals work and then moves on to diagnostics. She explains how the wiring works. If none of the signals are working, then the problem is likely in this order: Fuse(s) Flasher Switch Wiring If one or two signals are not working, then usually the bulb is the problem. Could be switch or bulb sockets or wiring but most likely is the bulbs. *The publisher and author cannot guarantee against unauthorized modifications of this information or improper use of this information. The publisher and author assume no liability for property damage or injury incurred as a result of any of the information contained in this video. Be sure to read and follow all safety instructions for any equipment seen or implied in this video, and use safe practices when working with potentially dangerous equipment. No information contained in this video shall create any express or implied warranty or guarantee. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user.*