I use a Golf 4 alternator on a Golf 4 as I saw fit. It runs fine, and there aren't any alarming sound. The problem is that it doesn't charge when I start the car. I have to rev the engine hard, and then it starts to charge normally. What the problem?


If the warning light is coming on when you rev the engine, check the light circuit. specifically, you should check the resistors in the gauge cluster.

Check the drive belt first for tension and wear. Also, make sure that the back wires are properly connected and clean. Then, check the voltage regulator.

Updated on March 19, 2018

Original Article:

Troubleshooting Alternator and Charging System Problems
By Dan Ferrell