The alternator in your Subaru Outback is the heart of the charging system. Without it, the battery would quickly run out of power and the engine would stall. Understanding that the battery starts the car and that the alternator charges the battery and supplies the electrical power requirements of the car is the key to troubleshooting the alternator; troubleshooting this key component of the charging system may seem like a daunting task, but it turns out to be a relatively simple procedure that involves conducting a few simple tests.
Turn your DVOM on and set it to read volts D/C. Attach the negative (black) lead on the DVOM to the negative battery terminal and the positive (red) lead on the meter to the positive battery terminal.