We're not seeing the ammeter in those photos.
The ammeter is further over toward the passenger side.
Red wire connects to the battery. Black wire to the main splice and the alternator.
View attachment 1715935574
(photo from this ad [SOLD] - 1964 Barracuda Valiant Gauge Cluster Ignition with key)
If you didn't see the ammeter peg or nearly peg in either direction, its possible that it was not damaged. The scale on the ammeter is 40 amps discharge to 40 amps charging. Different year ammeters were constructed differently so some are more tolerant of excessive current conditions than others.
Key checks will be
* for no damage to the insulation, including any fiber washers.
* The studs are firmly mounted in the metal plate that carries current.
* no damage to the needle mounting.
The goal is perfect connection between the two studs, and perfect isolation from any ground. Using an ohmeter there should be zero resistance between the studs. Ohmeters are not sensitive enough to pickup all poor connections but will let you catch the worst cases. The gage must be completely insulated from the instrument panel when installed. That can be checked visually and with an ohmeter.
We certainly see damage to wires and to the alternator.
If you did not see high charging for long period of time on the ammeter, then I'm leaning toward a short to ground in the main circuits. It is certainly possible the short was in the alternator itself.
In 1965 Chrysler added a fusible link to the battery wire to help protect the rest of the main circuit from this type of short.
Here's how a fusible link works, and how it can help when any wire connected to the battery, including the alternator output wire, gets grounded.
Voltage is excited electrons, or potential energy.
Current is electrons moving.
Current flow with engine running and the battery recharged would look like this.
View attachment 1715935590
If we measured it, the system is roughly at 14 volts when the alternator is working properly.
Lets say the headlight wire insulation got damaged and the car hit a bump such the bare wire touched the metal dash.
That easy path to ground kills the ignition and field.
View attachment 1715935588
However as voltage drops below 13 Volts, the path is clear for the battery to take the same opportunity.
View attachment 1715935589
If there is a fusible link, that should stop the current flow before too much damage.
View attachment 1715935591
I don't know that the problem was a short to ground in your car, but its a possibility.
If the short was after the fusebox, or after a circuit breaker (headlight and heater fan switches have CBs in them) I dont think we would see that damage on the alternator.
