[RichardJ]

The "F" stands for "Field". The Field Voltage of 11.3 V is way more that enough to start charging, so the alternator should be charging.

At this point I would say the regulator is good, BUT you still don't know. When the Alt starts charging, the output from terminal "R" will be roughly half the charging voltage. This voltage applied to #2, should close the Field relay, shorting #3 and #4 together. #4 will then read battery voltage , the same as #3.

You said you have two alternators so take them both in for testing.

If, and I believe they will test bad, have them also test a new one. They probably don't sell or test very many 10DN alternators anymore. The test machine and/or the tester may not be up to the task.