I guess this is technically HAMB friendly as the original Delcotron was indtroduced mid year 1962. I am converting my coupe from the infamous 10SI to the earlier 5.5"/1D externally regulated version. Everything works good as far as charging goes but the telltale light glows while the engine is running. I use a simple single position ignition switch in the coupe so I have no "acc" terminal. If you look at a GM factory service manual they show a 10ohm 6.25 watt resistor going from the "acc" side of the switch to the ground side of the telltale light, I do not have this for the reason posted above. I wonder if this is why my telltale glows while the engine runs? Anyone got any ideas on how to overcome this problem?