Brake Light Turn Signal Wiring Diagram. The brake light circuit can be a part of the turn signal circuit in some vehicle models. If your turn signal doesnt light up at all or doesnt flash it can often be a bad ground connection thats the culprit.
In modern vehicles the brake switch signal is also used to. Probe one of the pins with the multimeters negative side and the positive side of the. Check the switchs wiring diagram and find the single wire that establishes a connection between the brake light and turn signal switches.
Analog switches wear out over time and they can get dirty too which interferes with their ability to make positive contact and transmit the right signal.
Usa includes emergency light system created by bus owner. Then follow that wire color back to the battery. Consult your vehicle repair manual if necessary. I like to start.