Notes On Replacing Alternator Regulator On Three-Phase Alternator - AH15.40-P-1000-01Y

Engine 274 in model 213 

Picture 1 

Courtesy of MERCEDES-BENZ USA

Picture 2 

Courtesy of MERCEDES-BENZ USA

In the case of a complaint, the alternator regulator of the three-phase alternator can be replaced individually after the check and in the event of a defect.

For checks and tests on the three-phase alternator, always observe the work sequence in the relevant Service Information (SI).

With water-cooled three-phase alternators, due to the sealing concept, replacement of the alternator regulator is never approved. Improper repairs could lead to a total failure of the electrical system, causing further damage to the vehicle.

When removing the alternator regulator it is essential to pay attention to the length of the carbon brushes and the wear pattern on the brushes.

1. Check length of carbon brushes (A) of alternator regulator.

   If the minimum dimension of a carbon brush is not attained, the alternator regulator must be replaced (see picture 1).

2. Check shape of carbon brush wear.

   If the carbon brushes are worn at an angle (see picture 2, arrow), this indicates damage to the bearings of the three-phase alternator. Replace the three-phase alternator.