The alternator in a Subaru Outback operates various electrical devices in the vehicle while the engine is running. A voltage regulator keeps the voltage level constant and is usually part of the alternator assembly. You may need to replace the alternator if your headlights become dimmer while driving or your battery repeatedly runs down.
Determine which alternator your Subaru Outback will need. You'll want to be sure the new alternator is compatible with your Outback's engine. Models made from 1995 to 1999 can have a 2.2 L H4 or 2.5 L H4 engine. A 2.5 L H4 or 3.0 L H6 engine is available on 2000 to 2004 models. Models made after 2004 are offered with a 2.5 L H4, 2.5 L H4 turbo or 3.0 L H6 engine.
Disconnect the negative battery cable with a socket wrench. Remove the electrical connector and terminator nut from the alternator with a 10mm socket wrench. This will allow you to also remove the battery terminal wire from the alternator.
Remove the V-belt cover (if present) and mark the position of the adjustment screw. Loosen the front side V-belt.
Take the mounting bolts off of the alternator with a socket wrench and remove the alternator assembly from the vehicle.
Install the new alternator assembly and tighten the mounting bolts with a socket wrench.
Install the front side V-belt and the front side V-belt cover (if present). Adjust the belt tension to its original level by using the mark you made earlier. Connect the electrical connector and terminator wire to the alternator and attach the negative battery cable with a socket wrench.
