You were not "doubling" anything. Please read what I posted. Here is the issue:
On early (69/ earlier) systems with ONE field connection, the regulator FEEDS power to the field
On 70/ later systems where the alternator has TWO field connections, the ignition switch FEEDS power to ONE END of the field, and the remaining field connection "is to controlled to ground" by the regulator
IF YOU get
1--Either an early alternator (one field)
2--Or a late alternator with a SHORTED field connector,
3--or one of the rebuilts which I posted a photo of in the other thread, AND you hook the ignition feed (blue wire) to the "good" end of the field, the OTHER END of the field will be grounded, causing full unregulated output.
IN ADDITION if you are so unfortunate as to have a 70/ later alternator, with ONE BRUSH shorted, and you just happen to hook the blue wire to that shorted terminal, you will cause A LOT of harness damage, because the feed to that blue wire IS NOT FUSED.