Adding a tach, speed or "W" terminal on Bosch 1-wire alternators

Joined
Oct 14, 2005
Messages
326
Location
Schafflund, Germany
Some of these Bosch "1-wire" IF alternators with "multi function regulators" (MFR) have got a dedicated tach or "W" connector sticking out from the rectifier plate. Most however do not. I am wondering if there is a way of adding one without too much hacking and soldering.

If you look at the backside of the alternator with the regulator pointing upwards, the left most of the 3 bolt holding the regulator actually connects it to the rectifier plate. Isn't this just a direct connection to one of the stator leads? If so, all it takes to make a "W" is a hole in the plastic cover, a longer bolt, a spacer, and a ring terminal. Is it really that simple?
 
The tach function is just one of the stator wires but beware that a lot of current is available so something to limit the current like a resistor or fuse would be a good idea.
 
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