Subaru Impreza WRX Alternator Replacement: A DIY Guide for Canadians
Author : Amelia Lee | Published On : 26 Aug 2026
Understanding the Alternator's Role in Your WRX
The alternator is the heartbeat of your car's electrical system. While the battery gets your engine started, it's the alternator that keeps everything running once you're on the road. It charges the battery, powers the ignition system, runs your headlights, your boost gauge, your stereo, and in modern WRXs, it supports the ECU and a host of sensors.
In turbocharged applications like the WRX, the alternator works harder than in a typical commuter car. The demands of the boost controller, intercooler fans, and performance electronics put additional strain on the charging system. That's why alternator failure isn't uncommon in higher-mileage WRXs, and why sourcing the right replacement part matters more than people realize.
What to Know Before You Buy a Replacement Alternator
Not all alternators are created equal, and the WRX platform has a few variations worth knowing about. The generation and engine displacement of your car matters significantly when ordering parts.
For owners of the 2002–2007 WRX lineup running the EJ205 2.0L turbocharged engine, a standard replacement alternator for Subaru Impreza WRX is typically rated at 80–90 amps. However, if you've added aftermarket electronics, a bigger stereo system, or auxiliary lighting common in WRX builds you may want to step up to a higher-output unit to handle the extra electrical load
