Alt. not charging right.

[Charger4404spd]

I noticed my alternator isnt charging below 2000 rpm. Regulator fixing to crap out? At idle the volt meter will dip to less than 12 volts. From 1000 rpm to 2000, it will go to 14.5v.
Any ideas? Belt is tight, alternator was rebuilt back in the winter and just now using it.

[1974dodgecharger]

Mine did that for 3 weeks then one day I noticed a smell ,it kept driving.  Come home and noticed my belt was shredding due to looseness of the belt, kept slipping.


That's just me from noticing the charge not charging.

[Charger4404spd]

I got a 1 wire alt. from Summit. Installed it tonight and running 14v @ idle.