Wiring Car Repair Diagrams - Mitchell 1 DIY WIRING DIAGRAM COMPONENT LOCATIONS. When trying to locate a component in a wiring diagram and you don't know the specific system where it is located, use this handy component locator to find the system wiring diagram in which the component is located. Then, go to that system and locate the component within the wiring diagram. Why Don't My Brake Lights Work? - AxleAddict Aug 05, 2017Find the wiring diagram for your turn signal switch on your vehicle repair manual. 2. Locate the wire that goes from the brake light switch to the turn signal switch. 3. Get access to the turn signal switch electrical connector. Usually, you need to remove a cover off the steering column. Consult your vehicle repair manual, if necessary. 4.