Alternator upgrade questions for early cars

[240ZGL]

First off the car is a 73. I've done the alternator upgrade ( and the fuel pump relay problem) and headlight wiring harness. Everything worked great (about 6 month now) untill a week ago, dead battery and blown alternator and the diode on the upgrade plug was blow or melted.

I bought some new upgrade plugs, and replaced the alternator, charged the battery. The issue I found was the white/red wire coming off the voltage reg plug was burned up. I cut and jumped it down stream in the harness to some clean wire in the harness. Seems to be ok for now. Questions, the amp gauge moves around like a tach anything from the middle to a 50+ reading, is this normal ? If it's a 60 amp alternator shouldn't I be getting a 60 amp reading ?

Would upgrading the harness with larger gauge be worth the effort and where would you get color coded wire and plugs. Thanks

Edited January 9, 2012 by 240ZGL

[beermanpete]

It is unlikely you will see all 60 amps in the ammeter because some of the alternator's output goes to run the engine and other components in the car. The ammeter shows the current going into or our of the battery. If you are seeing 50 amps of charge for more than a moment at start-up you either have a discharged battery or the regulator is not working correctly and the battery is being overcharged. Check the voltage at the battery. When the car is not running it should be about 12.5. When the engine is running at idle is will be about 13 or so. When you race the engine is should rise to about 14.5 and stay there. Any higher than about 15 volts indicates a problem with the regulator.