76 Coronet charging problem

So a guy brought this really nice clean survivor type coronet in the shop and he has replaced the alternator and voltage regulator and it still wont charge. I gave the alternator full field and it charges 14.5 at idle and no I did not rev it up. Tried a VR off my duster that charges just fine and that made no difference. I am getting zero resistance between the VR and the alt on both wires, the VR feed wire is getting 12 volts and I made sure the VR case was grounded real good and it is real clean good ground under there, I even tried running a dedicated ground wire from the battery to the VR. Then one time out of the blue it started charging, then it quit and I was no longer getting the juice to the VR so I think I am having a wiring problem getting juice to the VR, my problem is I can not find a wiring diagram to find where there may be a splice or something causing an intermittent voltage drop issue. Does any one know of a common place to find this issue or maybe a wiring diagram and splice location for that system? I have alldata but it is more like allmostdata for the old good cars.

http://www.mymopar.com/index.php?pid=28
76 wiring diagrams.

Bad fusible link?

I'd concentrate on the blue ign1(run) circuit that feeds the charging circuit from the igns sw "ign1" terminal to the bulkhead then out to the alt field/VR blue feed wire, an intermittent open/poor connection. Unless wires have frayed insulation on the outside or strands are fried on the inside from a dead short at one time wiring goes bad at the end connections at the terminals from poor connections. Copper wiring does not deteriorate per se from an appropriate amt of currect simply flowing along it's length so I'd concentarate on the ends EDIT wiring also fails from excessive flexing breaking too many strands but this is a rare event & not the issue here. While running at an idle I'd use jumpers & see which one restores charging to pin down which circuit is open. Batt positive post to reg top terminal/to alt blue wire field terminal. alt is good reg is good reg/alt are grounded & there's continuity between alt/reg on the green wire circuit. That only leaves the blue "sense" wire that feeds switched 12V to the alt/reg