Mechanical Voltage Regulator Modification

[speedracer54]

For years my '71 911E has been over charging to the point that I could smell battery acid in the cockpit. As measured at the battery terminals I would see as much as 17 to 18 volts at idle! The 55A Motorola alternator is working normally per my friendly local alternator man.

Always wanting to retain the original alternator, and the appearance of the SEV Motorola voltage regulator housing I searched for, and found a company that specializes in vintage alternators and VR; Precision Power of Lancing Michigan.

Precision Power was able to fit within the original VR housing, an electronic, solid state, regulator with an adjustable potentiometer! All wiring remained the same so simple as to just "plug 'n play" a stock wiring appearance is maintained!

I am able to achieve a charging no-load voltage of 13.8 to 14.2 with ease! Gone is the acid smell, and any acid overflow.

I hope this may help others in the same situation.

[speedracer54]

In this image, using a plug-in to the lighter volt meter, now charging at a respectable rate.

[john walker's workshop]

Looks like a standard vw/914 regulator, right out of the package. The adjuster is the giveaway.