Amp gauge showing around 20 amps whole time I was driving.
Not enough info to provide a specific answer.
But enough info to provide some guidance in solving the problems.
1. If the dead battery was charged by running the car, especially at high idle, then its possible that damaged occured.
2. Overheating of both the VR and the ECU could be from overvoltage, or damaged wires. Could be a short.
Post some photos and maybe one of us will see or can deduce something.
I would suggest investigating the components.
Start with the alternator. See if either brush is grounded (they shouldn't be for a 72)
With the green field wire (R3) disconnected from the alternator, check if that is grounded (it shouldn't be)
Not all 72 Model year cars came with the ECU. Although those that did, came with the double resistor. On is 5 ohms and helps regulate power to the ECU. The other is 0.5 ohms and controls power to the coil (except at start).
Functional Schematic for isolated field alternator and original ECU ignition
Alternator brushes and field terminals shown here
https://www.forabodiesonly.com/mopar/threads/identifying-chrysler-alternators-1960-1976.475691/
Not enough info to provide a specific answer.
But enough info to provide some guidance in solving the problems.
1. If the dead battery was charged by running the car, especially at high idle, then its possible that damaged occured.
2. Overheating of both the VR and the ECU could be from overvoltage, or damaged wires. Could be a short.
Post some photos and maybe one of us will see or can deduce something.
I would suggest investigating the components.
Start with the alternator. See if either brush is grounded (they shouldn't be for a 72)
With the green field wire (R3) disconnected from the alternator, check if that is grounded (it shouldn't be)
Not all 72 Model year cars came with the ECU. Although those that did, came with the double resistor. On is 5 ohms and helps regulate power to the ECU. The other is 0.5 ohms and controls power to the coil (except at start).
Functional Schematic for isolated field alternator and original ECU ignition
Alternator brushes and field terminals shown here
https://www.forabodiesonly.com/mopar/threads/identifying-chrysler-alternators-1960-1976.475691/
