I assume you'd like to test the Rectifier next?
Disconnect it from the wire harness. Test it "out of Circuit".
The meter selector will be changed to the position next to 200Ω, on the symbol that looks like -<|-.
This is the diode setting, which makes the meter supply enough voltage to turn on functional diodes and make them conduct.
There are six diodes in the rectifier. Their purpose is to convert the AC current made in the alternator, to DC current which can be used by the battery to restore power that was drained from it. The diodes do this by only allowing current to flow in one direction. You will now test them for this correct function.
Select a probe polarity and apply the probes to each yellow wire and the
green wire. Record the 3 meter readings.
Now switch the probes, which reverses the polarity, and again apply them to each yellow and green wire. Record the 3 meter readings.
That just tested three of the diodes.
Now do the other three by applying the probes to the yellow and
RED terminals. Record the 3 meter readings.
Again switch the probe polarity test the yellow and RED terminals again. Record the 3 meter readings.
What you should have as a result is six readings that are very high, and six readings that are very low. This would show that each diode will conduct current in only one direction. If any diodes are burned open, they will never show a low reading. If any diodes are shorted, they will never show a very high reading. You should now know if your rectifier is good or bad.
If you want to move toward testing the wiring components. Then disconnect the battery at it's terminals. Then set the meter back to the 200Ω scale. At the bike harness connector where the rectifier plugs in, place one probe on the green terminal and the other probe on the battery NEG cable terminal (NOT the battery itself). Record and report the reading.
Repeat the same test probing the Red connector terminal and the battery POS cable terminal. Record and report the results.
What you are looking for in both these tests is very low resistance in both cases, which shows proper connectivity of the charging system components to the battery terminals.
Next we will do voltage testing.
Move the selector knob on the meter to the DCV 20 position.
Place the probes on the battery terminals. A fully charged battery that has been removed from the charger for two hours should read between 12.6 and 12.8V. Tell us what your battery tests.
If you have found no faults or tests that are out of limits so far, then reconnect the battery and the rectifier to the bike. Find a separate insulated wire that you can attach between the battery POS terminal and the White wire to the alternator. (Assuming the Vreg is removed from or unconnected to the bike harness.) Alligator clips would be of help here.
Start the bike and monitor the battery voltage. Record and report the voltage at 1000 RPM and in 1000 RPM increments up to 5000 RPM.
Discontinue the testing if or when the battery voltage rises to 14.5- 15V. Such an indication will prove the alternator capable of charging the battery.
Which leaves two more tests.
With the bike not running and the key switch on, the black wire to the Vreg should have battery voltage on it. Probe any green connection, (or battery NEG terminal) along with the black wire, and you should see 12.(something) volts, or whatever the battery voltage potential is.
If that is what you get, then the last thing to test is the Voltage regulator.
Let me know when you get this far, and we can continue from there. If the bike still won't charge the battery with the Vreg you have installed, we can find out why or perhaps even fix it with a light massage.
Cheers,