BMW Airhead Boxer voltage rectifier/regulator

BMW Airhead Boxer voltage rectifier/regulator

BMW Airhead Boxer voltage rectifier/regulator for traditional wet lead acid & AGM batteries.


BMW Airhead Boxer 14.2v voltage rectifier & regulator unit.

Replaces the original BMW diode board and voltage regulator so 2:1 unit.

Designed to fit all BMW R2v Airhead Boxer models including:

  • BMW /5 Series (70-73)
  • BMW /6 Series (73-76)
  • BMW /7 Series (76-84)
  • BMW R45/65 (78-84)
  • BMW R80 G/S
  • BMW R80 ST
  • BMW Monolever (85-96)
  • BMW R80/R100 GS Paralaver
  • BMW R100 R & Mystic Paralever

High quality replacement regulator/rectifier unit, designed to replace the original separate regulator and diode board (rectifier) that were part of original Bosch alternators/charge systems fitted to these BMW R2v Airhead Boxers.

This voltage regulator/rectifier is supplied complete with a long wiring harness that connects directly to the alternator stator and to the brushes.  

The output wires are connected to the battery terminals making this setup highly efficient, thus avoiding having to rely on the often damaged or corroded original wiring and connectors.

Rugged construction, built using modern materials and technology, it offers superb performance, with a more stable battery charge thus a longer working life.


  • Width:   71mm
  • Length: 81mm
  • Heigth: 29mm
  • Centre to centre bolt fixation: 60mm
  • Wires lenght: 1030, 1450 & 1530mm


  • Yellow -    Alternator Stator (x3)
  • Black -     Alternator brush holder D- (negative)
  • Brown -    Alternator brush holder DF (positive)
  • Red -       Battery + (positive) - ideally via 30amp fuse (not supplied)
  • Green -    Battery - (negative) - ideally directly to the battery negative post or a good earthing point on the frame
  • Orange    Switch on (positive) power source - Green/blue wire for example feeding the coils or on the ignition switch.


 1 - This unit does NOT provide a charge warning light connection (blue wire out of the back of the original diode board/white connector above engine). Requires alternative wiring to a switched on power source (green wire for coil or ignition switch).

2 - NOT suitable for Lithium type batteries. Use ONLY with lead acid batteries including AGM type such as made by Motobatt & Odyssey. Warranty will be void if unit used with a Lithium battery. 

3 - Suitable up to 450W/50amp charging systems.

4 - Slight tweaks to fit to the various BMW frames required as well re-routing its wiring harness. It should be ideally placed on the frame, away from heat sources. It will NOT fit in lieu of the original diode board. It may require suitable mounting plate fabrication.

5 - We do NOT accept returns & refunds on this item as electronic components are easily damaged by incorrect installation or swapping parts for a diagnostic. If suspected faulty, we will ask for its return to us for further testing.

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£0.00 £89.99
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