Dana67Dart said

First and foremost...
What car?
What year?
Post photos of the front and back of your alternator
Post photos of your voltage regulator

Then....


Assuming the alternator is properly wired as a 1 field wire alternator, grounding the 1 field wire terminal on the alternator would produce no charging from the alternator.

If you ground the 1 field wire from the voltage regulator you will burn out the voltage regulator.

Some simple tests
With the engine running, measure voltage from battery negative to the following points

1. Input to the voltage regulator
2. Output from the voltage regulator
3. Input to the field terminal on the altrnator
4. Output from the alternator charge post
5. Positive post on the battery

Record the values and report back

Click to expand...