Well Gents,
1970 Thunderbird
Here it is. Car seemed to be running off the battery. Voltage would drop and drop until it wouldn't start. Voltage meter on fully charged read 12.7 not running. After starting, voltage dropped to 12.58 and contined to drop quite gradually to 12.26. Alternator battery lead reads same voltage as battery. Figured it should be reading a higher voltage ie 14.2 volts or so.
Interpreted low voltage as malfunctioning alternator. Purchased a new reman. Installed it. Nightmare begins to grow. No power to the car anywhere. As a test, put a jumper on positive batt to alternator pos. Success car starts, but new alternator voltage reads same as battery as before. Indicating that the previous alternator was fine and problem lies elsewhere.
so, two problems arise.
1) While I was quite careful with the wires while moving new alternator into place, apparently, there is a newly created lack of continuity.
2)Even with power at alternator, the voltage is low indicating a malfunctioning voltage regulator.
Any tips on isolating the continuity problem other than patience and unwrapping the factory harness? Acceptable solutions.
Regulator identification. I believe mine has been replaced and am somewhat uncomfortable wtih the testing nothing under the hood looks like the regulators in the Shop Manual. The item I believe is the regulator in mounted on a box on the firewall very close to the power assist for the brakes. Make sense? More info required? Let me know.

Sorry. One more bit. There is some mention of a fuseable link that I haven't seen or located. Is it possible this has created the lack of continuity after an indavertent an unnoticed short when tightening fld and neg connectors to alternator.

Had a similar problem with a '77 Lincoln. There is a wire from the ignition switch that supplies 12 volts to the voltage regulator when the key is in the on position. I lost continuity in that wire and the car wasn't charging, even after installing a new alternator and regulator. I replaced that wire and everything was fine. If you can find the correct terminal on the regulator you can put a jumper from the pos of the battery to that terminal and see what happens. Good luck.

Thanks Jim.
Identified the regulator location. On the Rad support right beside the battery. This definitely is a regualtor from a Mustang but may or may not be working. Apparently the air and signals are not wokring after I finally got it running.
Most recently, I put a jumper on from the alternator to the pos on the battery and amazingly all power cpomes on an all works except still not charging. Thinking it may be possible that the alternator is not working.

WEll. All good. Found 3 blown fusible links with the help of my friendly old car friendly garage, Thee AC was a vacuum hose. My bad. Mosyt recent problem is overheat. Taken care of now after thermostat installed and oil changed due to 2 heat stalls.