1. Delcotron was an externally regulated alternator. It was used with a separate voltage regulator. Was called a Delcotron Generator. The name in my opinion refers to a externally regulated "alternator". It's claim to fame was a diode rectifier and rotor/stator/slip ring design.

2. The "modern" 10SI Delco is an internally regulated alternator. It can be wired with or without an indicator light.
There are folks who's motor "ran on" and they fixed it with a light or resistor or a diode. There are many folks who have none of those and have no trouble. Mad Electric said you DO NOT need a light or etc.
Each "run on" situation has to be examined for how and where the "switched" exciter power is wired. What terminal on the ignition switch and if ammeter or volt meter.
I have not studied why some with no light, resistor or diode have a problem and some don't. You would have to do some testing while it's "running on".
If a person has an ignition switch with a "ACC" terminal I believe that is isolated from IGN ON. The ACC terminal would be used for alternator pin 1.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn