Alternator problems are wreaking havoc on 1978 ford LTD

Okay, basically, i've been looking for the problem for the past month. I've changed my alternator twice to swap it out, and tried multiple different terminal to post connections, as you can see, it might be wrong, but i can't find anything i can understand on how to hook it up.
http://img541.imageshack.us/img541/2715/photo0113k.jpg

and i can't pull a voltage over 12.7, and thats not running. running the highest i've gotten was 12.3 i think? i've had everything tested by oriellys and autozone both, and they can't find the problem. i'm completely dumbfounded, and this is my last call for help before i take it to the shop.

things i've done:

alternator change (x2)
voltage reg
battery terminals (i cleaned them)
checked the ground to the block
checked belts
removed power to radio
revved engine

still no alternator power?

helpppppp

Hi, welcome to the forum. I don't know anything about your vehicle but I had a look at the wiring diagram on the Autozone website (Repair Info section). If the diagram is correct (sometimes they aren't; especially on older vehicles) then you have a fusible link in the alternator's main output feed to the battery. If you have a multimeter then it's easy to check the fusible link even if you don't know where it's located. With the engine off and the ignition also switched off, check for 12 volts on the alternator's main output terminal - that's the heavy gauge black wire which connects to the stud with the red plastic insulator on the right of your photo. Multimeter set to measure DC volts, black meter probe connected to a good ground point, and use the red meter probe to probe that output stud - if you have 12V on the stud then the fuse is intact, but if not then the fuse is open-circuit. That would be the obvious first check.

This is the wiring diagram - alternator at bottom left of page: Link (http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/05/3e/b3/large/0900c15280053eb3.gif). If that link doesn't work then try this one (http://www.autozone.com/autozone/repairinfo/repairguide/repaiguideOverlay.jsp?src=http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/05/3e/b3/large/0900c15280053eb3.&imageType=gif&imageName=Fig.%20%2020:%20Engine%20control%20schem atic-1978%20models). And remember you have both the engine and ignition switched off while doing that.

You have an external voltage regulator. If it is bad, the alternator will not work even if its good/new.