Understanding a 2 prong flasher wiring diagram is crucial for anyone working on vehicle electrical systems, particularly for older vehicles or specific trailer applications. This diagram serves as a blueprint, detailing how a two-terminal flasher unit connects to your vehicle's turn signal system. It’s a relatively simple setup, but knowing the exact connections ensures your turn signals operate correctly and safely.
What is a 2 Prong Flasher and How It Works
A 2 prong flasher, often referred to as a thermal flasher or blinker, is an electro-mechanical device that interrupts the flow of current to your turn signal bulbs, causing them to flash on and off. Unlike modern electronic flashers, these older style units use a bimetallic strip that heats up and bends, breaking the circuit. As it cools, it springs back, reconnecting the circuit and starting the flashing cycle again. This consistent interruption creates the distinctive blinking effect. The correct wiring of a 2 prong flasher wiring diagram is essential for the entire turn signal system to function.
The 2 prong flasher wiring diagram typically shows two terminals. One terminal, often labeled 'P' for power or 'L' for load, connects to the vehicle's battery or ignition switch, providing the electrical power. The other terminal, usually labeled 'L' for load or 'B' for bulb, connects to the turn signal switch and subsequently to the front and rear turn signal bulbs on one side of the vehicle. When the turn signal switch is activated, it directs power through the flasher unit to the bulbs. The flasher's internal mechanism then takes over, rapidly switching the power on and off.
Here's a simplified breakdown of the connections you might find in a typical 2 prong flasher wiring diagram:
- Power Input: This wire comes from the vehicle's fuse box or ignition switch, supplying constant power when the ignition is on.
- Output to Signal: This wire runs to the turn signal switch.
This simple circuit ensures that when you activate your turn signal, the bulbs illuminate, and the 2 prong flasher unit provides the automatic on-off blinking action. The absence of a third terminal means that the flasher unit itself is not grounded through a separate wire; instead, it typically relies on its mounting or the vehicle's chassis for a ground connection.
To properly understand and implement a 2 prong flasher wiring diagram, refer to the detailed schematics and guides available in reputable automotive repair manuals specific to your vehicle's make and model. These resources provide the most accurate and up-to-date information for your specific application.