I was told the reason Mopar went to the shunt type amp gauge was because so many customers complained about the amp gauge going to discharge at an idle at night with the lights and maybe the heater on. And I do know that many of the shunt amp gauges in some Mopars never moved much. I remember my moms 74 Monaco wagon that had a shunt stye amp gauge and I know when I turned the headlites on with the car off I could not see that amp gauge move at all. Course on the non shunt type like the 60's Mopars used the amp gauge would go way over to discharge if you turned the lights on with the eng off. So it made me wonder if they went with to much on the shunt where it was carrying more then 90% of the load on some ? And most customers never knew as they just new the amp gauge did not go to discharge at idle at night. But I always felt the shunt style did not give the customer a very good watch of the charging system as I felt even if it stopped charging it wont be seen right away. Ron