i need help soon.. electrical problem
So I buy that install it and then do the thing with meter?
Yes. If the wiring is correct and the voltage regulator is working correctly, one of the small terminals (blue wire) on the alternator should read constant battery voltage (~13.4 V) and the other small terminal (green wire) will read a low voltage (<10 V) when the alternator is generating current (turn on headlights and all accessories) and close to battery voltage when no current is needed (turn off headlights). Connect the multimeter black lead (-) to battery- and the red lead (+) to whatever voltage you want to measure. Of course turn it to "VDC" and "20" range (or higher).
If you want to save money, buy the multimeter first and see if the problem is in the wiring. Unplug the connector at the voltage regulator. Unplug the green wire at the alternator. Turn the multimeter to "ohms" (upside-down U symbol) and lowest range. Connect black lead to battery- and the red lead to the green wire of the voltage reg connector. If you measure less than 100 ohms, that means your "field control" wire is shorted somewhere. That would make the alternator put out max current.
On a side note, RedFish is slightly wrong. As 67Dart273 posted, there are several styles of the "pre-70" voltage regulator (i.e. "grounded field" or "1 field wire"). He showed the factory original and one electronic replacement. I have an electronic one on my 65 Newport that is a silver box about the same dimensions as the 70+ one, but with the same connectors as the old factory box. Those are still available (~$25) and are best for people upgrading who don't care to run a new wire and hack up their wiring. Such "high side throttling" should work as well as the 70+ type's "low side throttling". To tell if you have the 70+ style box, go by the triangular connector with 2 pins, not the shape or color of the box.
