[Ford-ferguson] 1952 TO30 alternator

[Rick]

I just replaced the battery and noted that the AMP meter
isn't charging. I recently replaced the single wire lead from the
alternator that was two wires (wire-nutted) under some hydraulic hoses, with a 10ga single wire point to point.
Is this the only wire needed?
The wiring may have been wrong from the time I bought it
3 months ago. It seems odd that wven though it has a built-in
regulator to only have the one wire going back to the meter.

Rick