1972 dart alternator pulley shaft question

13.3 is low, but it might be the battery is still low. Charge it up if you can or run it awhile and recheck. With battery "up and normal" AND ENGINE WARM (the VR is temp compensated) battery should run 13.8--14.2 +/- a couple of points


ok i just took it out for about 20 miles , lights on though cuz it got dark , rechecked showing 12.73 at idle , 13.43 to 13.45 at fast idle , stayed same if i open the throttle full . so its a little better , but not much .