Vetus Technical Service Mail: New Alternator for M3.28/M3.29 Engines
Date: Schiedam, August 2025
Subject: New alternator M3.28, M3.29
Product Group: Engine Engines
Article Code: STM7437
Delivery Date: [Not specified in document]
Introduction of the New Alternator
With the introduction of the new engine M3.29 (also for the M3.28 engine), a new alternator with part number 19-17663 (previously 08-01394) has been introduced.
This part will also be used as a spare part, replacing the current alternator STM7437. The new alternator differs from the old one but can be used to replace the STM7437 on the M3.28 and M3.29 engines. However, the wiring needs to be modified for this purpose.
To replace the alternator on the M3.28 and M3.29 engines, it is required to order an additional kit with items to fit the alternator correctly on the engine. The number of this kit is 08-013942.
Contents of Kit 08-013942
- 08-0188: 1x
- STM1030: 1x
- 08-01497: 1x
- 08-01389: 2x
- 08-01390: 1x
- 90° angle connector: 1x
Installation and Parts Information
Diagrammatic Overview
Diagram 1: Mounting the STM7437 - Shows the older STM7437 alternator with numbered components (1-13) indicating mounting points and connections.
Diagram 2: Mounting the New Alternator - Illustrates the new alternator with numbered components (1-17) detailing mounting and connection points.
Parts Replacement and Requirements
Parts No Longer Used After Conversion
- Part nr 3 (STM4537) will be replaced by 08-01388.
- Part nr 7 (STM1024) will be replaced by STM1030.
New Parts Needed for New Alternator
- nr 15: 08-01497 (bolt M6x65)
- nr 16: 08-01389 (ring 16 mm)
- nr 17: 08-01390 (ring 20 mm)
Wiring Adaptation
To accommodate the new alternator with the wiring, modifications to the wiring are necessary.
Wiring Details for STM 7437 (Old Alternator)
Image 1: Vetus STM 7437 alternator with an arrow pointing to a specific connector.
Image 2: An alternator connector is shown with a red cross symbol ❌, indicating that the connector for the warning light and excitation must be removed by cutting the wiring.
The yellow/green wire requires a 6 mm cable eye, and the purple wire should be insulated (not to be used).
Image 3: Shows the mounted 6mm cable eye and the insulated purple cable.
Wiring Details for New Alternator
Image 4: New alternator with labels identifying connection points: 'W connection for the tachometer', 'B+ main + connector', and 'L connection for the warning light'.
The W connection (grey wire) should be fitted with a 90° angle connector (included in the kit).
The green/yellow wire connects to the L connector of the alternator.
The thick red wire is for the B+ main connector.
Image 5: Depicts the connected alternator with the wires correctly attached.
