Blowing voltage regulators

Dodge6719 said

Only the regulator, first time alternator of natural causes.

This is the points type regulator

Click to expand...

Sorry I wasn't clear.
Inside there is an electromagnet and a set of double points.
Underneath, there are resistors.
There's also a fuse wire.
Look at which one failed. This will be the first clue as to what went wrong.