Sxrxnr. I agree with everything you wrote. Good real life example.
Driving on the way to the event, amp meter is pegged at full charge, now I am worried that I am going to burn up the alternator best case, or worst burn up the car because of excessively long period of alt current passing thru amp gauge.
The alternator should not burn up. It may run warmer because its providing closer to its max output for the given rpm for extended period of time. But stock units have adequate cooling for their original internals. Nothing to write home about but nothing to worry about either.
You are correct to be somewhat concerned about wiring of the the charge circuit if it is pegged. From the main junction to the battery there are several connectors and the wires themselves are not particularly heavy. The wires are protected to some degree by the fusible link. The old connections are potentially the most vulnerable to developing resistance; oxidation or loose terminals.
If the ammeter peggs to charge, best move is to shut down. Pegged indicates its (current) is above the design limits for the circuit even if everything is in good shape. Letting the battery cool down (especially with an AGM battery) helps it recharge.
If the meter showing charge, but less than pegged, run at low rpm and or turn on headlights. If the meter doesn't come down over time then the VR is still calling for recharge because the battery is not taking the charge or is really low. Shut down, let the battery cool.
If the ammeter pegs to discharge, shut down asap. The battery can provide a couple of hundred amps if asked.
The fusible link should deny it, but if its asked for just 50 or 100 amps it might be not open before something in circuit - usually a connection melts open.
Nacho's diagrams of the Charging Circuit make it easier to see the connections. no pun intended..
