Click here for more information and related products: https://mercedessource.com/problems/engine/inspecting-the-voltage-regulator-it-fails-and-leaves-you-stranded – As these old Mercedes approach 20+ years the brushes are wearing out and the alternators are failing. Many owners are having their expensive alternators replaced without knowing that it might just be the inexpensive voltage regulator mounted on the back on the alternator.