ammeter

Actually the above is only partly correct. Running a direct wire to the battery does nothing if your trouble is in reality the bulkhead connector, which is much much more likely to be damaged than the ammeter

Please read this article

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

One reason I re-re-re-re-re re........post this so often, is that it's an excellent article. I shows the whys and hows of how this stuff goes wrong

If you have a completely factory stock car, and the bulkhead connector is brought up to "as new" with a stock alternator, you likely can get by fine.

All these old girls, however ARE under-fused compared to newer stuff