Fluttering Voltage, Backfire, Engine Quits

[3yearcuda]

Hello. Running original wiring in restored 69 Cuda. Have the usual issues as with any other Mopar I've owned ie: dim lights, slow signal lights with headlights on, voltage shows low at idle, etc, etc.
But.....the other day out for a cruise and all of a sudden my voltage gauge tach's hard to the left (low), back to center and keeps fluttering while the car tries to die, then backfires, than goes again driving fine but with the voltage gauge still fluttering like crazy. The repeats with backfiring, engine trying to die, then volt gauge back to centre and drives normal till I get home. Once home and hood open I could hear my alternator (only a year old) rattling like a bearing was going or something.
I have never had this happen before. I have had an alternator give out in the past, but just wouldn't charge the system. Never a total kill of the engine and the voltage tach'ing erratically low like that. I just recently put a new voltage regulator, but maybe that's crapping out?
Are alternators known to do that at times? Is this what they call a "Dead Short"? Electrical is Voodoo to me, so I'm in the dark.
Any help would be very much appreciated.

 

[67Dart273]

Hard to say. You say "voltage" but if it's all factory you mean "ammeter" (should be 0 center?)

I would start by going over major connection points. This includes but not limited to:

Battery connections

Battery cables at starter

Connections esp the big post on starter relay

Disconnect the bulkhead connector and clean and inspect

Check rear of ammeter terminals for loose or heat damage.

Check the ignition switch connector and suspect the switch

The above is in no particular order. Also, was there smoke or smell?

 

[KitCarlson]

Also check engine to body ground strap.

 

[3yearcuda]

Thanks 67Dart273 for your quick reply, as well as your suggestion KitCarlson. I did just that and started going over major connection points, starting with the battery, then bulkhead connector. Then got thinking about that rattling alternator, so checked it and sure enough........a wire, i think Ignition wire had jumped off the FLD terminal and had been touching the outer case of the alternator. Upon closer inspection of the alternator, I could see melted wires within the alternator so just picked up another from the local parts store. I am assuming this was the issue, but wont be able to get the alternator back on until this weekend. I will be sure to post my results though once I get it back on so hopefully others can benefit from my experience and save a ton of time looking, or better yet.......be proactive and make sure those connections to the FLD posts are secure. Had that wire stuck to the alternator case, things would likely have been much, much worse. I'm feeling lucky.

 

[67Dart273]

I guess SO!! LOL. Years ago I had a loaner car. The alternator failed (out at NAS Miramar) and I got to watch as the entire engine harness welded itself into s smoking, stinking pile of blackened copper and plastic, AND THEN popped the fuse link!!!