A 12 volt draw on battery from a one wire alternator

You need to fix this before you start making mods, or pretty soon you will be in a REAL fix and I can't help you.

Let's go over this again:

1.........The alternator field is a MAGNET (electromagnet) When you feed battery power into one field terminal and ground the other you are activating that magnet. You need to make certain it is getting power and DRAWING CURRENT. This shows the field is good, and that the brushes are making contact and carrying current.

2....So........basics........take an "alligator clip" wire and hook to a battery source such as the starter relay large stud, and connect that to either alternator field terminal (blue and green hanging loose, disconnected)

3....Now take a second alligator lead and connect to the remaining alternator field terminal. You should see a small spark in subdued/ shaded light when you connect/ disconnect that wire. If you cannot see it hook your multimeter up to measure CURRENT

PLEASE POST a photo and or brand / model of your multimeter so we can help you hook this up.

Next, jumper one lead of the multimeter to ground, hook the other lead to the alternator field which DOES NOT have the battery jumper connected

The circuit should look like:

From starter relay big stud (battery)..........clip lead.........to one alternator field terminal.........through alternator field........other alternator field connected to one lead of multimeter in CURRENT mode.............remaining lead of multimeter grounded.

You should read more than 3A as much as maybe 4 or 5, and not more than 6A. Loosen the belt and turn the pulley on alternator to see if this varies