Alternator help

The voltage measurements indicate a drop of 1.3V from battery thru bulkhead, ignition switch, and back thru bukhead. That is too much, only a few tenths is acceptable. Also check voltage from regulator the case where it bolts to body to battery negative. It should be close to zero volts.

Typically what happens is the alternator will put out 13.8V plus the 1.3V, or about 15.1V, too high of voltage. Since that is not happening, other problems exist too.

If the green wire is detached from regulator, and connected connected to battery plus, while monitoring battery voltage, the alternator can be checked. The engine speed can be increased, but do not let the battery voltage exceed 14.V. There is a significant shock hazzard, so be careful when you make and break field connection to battery. If voltage is a maximum of 13V, in first post, the alternator or other connections could be at fault.