GM charging system - Alt w/ Ext regulator charging but light on

I've got one of my Chevy IIs that is giving me problems. It is a '63 with an alternator with an external volt regulator.

Problem was it is not charging. No volt light on dash

1. Changed the volt regulator - still not charging

2. Changed alternator to an old one laying around - now charging about 14 volts [color:"red"] now the VOLT light is on

3. Put old reg back on. - volt light out, not charging, battery voltage.

4. Got alternator back from being rebuilt, new regulator reinstalled. - now charging, but [color:"red"] VOLT light on again .

Any ideas as to what the problem might be? It's probably something simple I'm forgetting to check.

You're sure that the bulb in the dash indicator is good, huh? I had a problem once with the '69 Cutlass wagon, the lamp burned out and the car wouldn't charge, but of course no indicator light because the lamp was burned out... and on GM cars of that vintage with a lamp instead of a gauge, the lamp is an active part of the system and has to be good for the charging system to work properly.

Sounds like that's probably not the case here tho, but worth knowing about.

Another idea... I've had 2 cars where one of the wires going into the alternator plug has been hanging by only one or two strands, and you can't see that unless you really look for it... or the wire falls off the plug when you touch it!

Good luck - hope some of this helps a little.

the bulb is good as it does light up, just can't get it go out when the charging system is actually charging that battery.

I have double checked as someone else recommended that all the fuses are ok, which they are.

I'll take another good look at the wiring harness.