Not charging with headlights on

cadboy,
You didn't list results for all the tests. Don't condemn the alternator until you measure no output (big stud) with 12 V across the field terminals. Most round-back alternators ground one of the field terminals to the case (info above). Even then, the alternator may not be bad, it may just not be getting a good ground to the engine. Insure the case voltage is close to BATT- to check that.

trebor75, before you condemn your Vreg, insure it is getting +12 V supply from the ignition key. That is the voltage it senses and attempts to regulate to ~13.4 V.