Do we need to replace alternator for bad voltage regulator on 2007 Toyota RAV4?

My mother’s 2007 Toyota RAV4 was recently diagnosed with a faulty voltage regulator by an auto parts store after it had died a few times when sitting off with lights on for brief periods. The replacement of the alternator seems quite daunting, so I recommended they take it to a repair shop to have it fixed rather than me doing it.

What they want to know is whether they need to replace the alternator since the problem isn’t too debilitating, or if the problem will keep getting worse so they might as well do it sooner rather than later.


If the alternator (with internal voltage regulator) is faulty, the car will continually stop running. The regulator may have “half” failed so it charges a little bit but that is the only thing that charges the battery while driving. Driving the car requires electrical power to run the fuel pump, fuel injectors, ignition, and on and on.

You really have 2 choices, replace the alternator or stop driving the car.


Got it, thanks.