Brushes are shorted to ground.

I don't understand how it could charge if the VR connector "fell off"

The alternator may not be "toast" depending on whether you can get brushes and the insulation hardware. My last foray into NAPA did not end well. I ended up ordering 3 sets of brushes over 3 days, and at least two of the three had different hardware!!! I finally mixed and matched the 3 kits to produce 1 usable set, threw the rest of the parts in the 3rd box, and took it back and told them to turn it in as "defective." He had NO IDEA WTH that meant!!!

But yes, the normal condition is NO continuity to ground from either brush, in other words "infinity." If you can't figure it out, remove the brushes one at a time and re-check, then LEAVE them out and check from ground directly to the slip rings. It is possible for the rotor to short