Parts for your 2014 Subaru Forester-Alternator

2014 Subaru Forester alternator

Based on technical references, the 2014 Subaru Forester absolutely uses an alternator. Subaru’s Forester SJ (2014) Service Manual – Charging System describes a belt‑driven alternator with an internal regulator under ECU control. The Subaru Electronic Parts Catalogue lists alternator assemblies across the FB20/FB25 petrol, FA20 turbo, and EE20 diesel variants, and industry catalogues from Denso and Bosch list direct-fit alternators for these engines. Factory wiring diagrams also show the charge warning circuit and ECU field control for the alternator.

For the 2014 Forester, the alternator’s job is straightforward: keep the battery topped up and feed power to everything electrical while the engine’s running – from the headlights and demister to the stereo and safety systems. Subaru fitted these models with an internally regulated, ECU‑managed “smart” alternator, so charging voltage can vary a bit depending on load and driving conditions to look after battery health and fuel economy.

As part of regular servicing, it pays to give the alternator and drive system a once‑over. Inspect the serpentine belt for cracks or glazing and make sure the automatic tensioner is tracking smoothly. A quick charging check at the battery with a multimeter should show roughly 13.8–14.7 volts with the engine idling, switch on lights, rear demister and blower to confirm it holds up under load. If the charge light flickers, the lights pulse, there’s a high‑pitched whine, or there’s a sulphur smell from an overworked battery, it’s time to dig deeper.

When replacement is due, using a quality OEM‑equivalent (commonly Denso on Subaru) keeps noise down and output stable. Disconnect the negative battery terminal first, protect the ECU from voltage spikes, and check all engine and body earths are clean and tight when refitting. Many SJ Foresters use a decoupler/overrunning pulley on the alternator, if fitted, make sure the new unit has the correct pulley style. After install, verify charge voltage and look for AC ripple (excess ripple hints at a bad diode). No fancy coding is typically required on these – the ECU adapts automatically – but an idle relearn and clearing any stored charging DTCs is good practice.

A quick alternator and belt check every 10,000–15,000 km suits most Aussie and Kiwi service intervals, especially if the vehicle does short trips or tows. It’s a small effort that saves batteries and keeps the Forester’s electrics happy.

Popular questions about the 2014 Subaru Forester alternator

What charging voltage should a 2014 Forester show?
With the engine idling and a healthy battery, expect roughly 13.8–14.7 V at the battery posts. Because Subaru uses smart charging, voltage can dip or climb briefly with load and temperature. With lights, fan and demister on, it should still sit in the mid‑13s to low‑14s. If it’s stuck near battery voltage (around 12.2–12.6 V) while running, charging isn’t happening.

How can they tell if it’s the alternator or the battery?
If the battery is old or has been flattened, test or charge it first. Then check running voltage and look for the charge light. A weak battery that cranks slowly but charges fine when running points to the battery. Dim lights, electrical gremlins at idle, or more than about 0.3–0.5 V AC ripple at the battery suggest alternator or diode issues. Many parts stores can load‑test both in a few minutes.

Does the 2014 Forester need alternator coding after replacement?
Generally, no. These Subarus don’t require scan‑tool coding for a new alternator. Fit the correct spec unit, ensure good grounds, clear any stored fault codes and, if needed, perform an idle relearn. The ECU will manage field control and charging strategy on its own.