Making the Bosch (and Wehrle) Metal Can Electronic Voltage Regulators Adjustable.

I wrote this article because a few people asked for it. You can purchase an adjustable voltage regulator quite reasonably from or But, the stock metal can regulators are not difficult to modify, the cost is very low, and you get to keep the original stock appearance …if you want-to. The metal-can VR’s are very reliable ….and are relatively easy to repair. They can even be modified to work with very high powered alternators for the Airheads (by changing the power transistor inside). These metal can regulators, no matter the name on them, MIGHT have been made by Bosch or Wehrle.

The exact same procedure is involved….(and the same hole drilling and adding a grommet, if you want to). Here is a photo of the Wehrle METAL CAN Electronic Regulator, with the potentiometer, with factory sealing paint. This is a how-to article, the purpose is to make your Bosch or Wehrle ELECTRONIC metal can unit easily adjustable.  This article is NOT for the similar (but taller) metal can mechanical Bosch regulator…see   

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