The wires on an alternator carry electrical current to charge your vehicle's battery and power its electrical system.
Here's a breakdown of the most common alternator wires:
Main Output Wire (B+)
- This is the largest wire connected to the alternator.
- It carries the primary electrical output from the alternator to the battery's positive terminal.
- The heavy gauge of the wire ensures it can handle the high current needed for charging.
Field Wire (S)
- This wire controls the strength of the magnetic field in the alternator.
- The stronger the field, the more electrical power the alternator generates.
- It often connects to a voltage regulator, which monitors the battery's charge and adjusts the field wire's current accordingly.
Sense Wire (L)
- This wire carries a small current from the battery's positive terminal to the alternator's regulator.
- The regulator uses this information to monitor the battery's voltage and adjust the alternator's output accordingly.
Warning Light Wire (W)
- This wire connects to the charging indicator light on your dashboard.
- If the alternator is not producing enough power, the light will illuminate, indicating a potential issue.
These wires work together to ensure your battery is properly charged and your vehicle's electrical system is functioning correctly.