I hate to be the bearer of neg news, but you might not have fixed it. you may have a poor connection causing the low blue wire voltage and when you wiggled around changing the regulator, you "wiggled" the connection "good." Keep an eye on it!!
The general problem "most of the time" is the functional path from the battery to the regulator. Generally, that path is battery......starter relay stud..........fuse link...........through the bulkhead on ammeter RED, to and through the ammeter.........on the BLACK ammeter wire........to the WELDED SPLICE........branch to the ignition switch connector--------through the switch..........out the switch connector on IGN2......out into the engine bay through the bulkhead connector (dark blue)............to the ignition system, alternator field, regulator, etc.
The worst offenders seem to be the bulkhead connector terminals, the ammeter, and the ignition switch and switch connectors.
Again, one easy way around this is to (electrically) chop the blue IGN2 after it enters the engine bay, use the bulkhead connector end to feed a bosch relay, and feed the relay contacts through a fuse/ breaker off the starter relay stud. Connect the load contact to the cut engine bay end of the dark blue.
THIS WILL CAUSE the ammeter to "offset" a few amps but it should give the regulator "exact" battery voltage
