Charging issue

[terraformer]

I just bought a 1970 318 Challenger (which was rebuilt just before sale to 340) and it appears that since the rebuild the battery hasn't been charging (I basically bought it from someone who gave up). It runs fine off of the battery, but the alternator is not providing power to the battery to recharge. I swapped out the alternator, the VR and still no joy. This has had an MSD ignition in it for some time for there is a jumper on a factory harness right behind the distributor. This is a straight pipe (with resonators) so I am trying not to tick off my neighbors and diagnose most of this as per the wiring diagram before having to run the thing. I have the wiring diagrams but the MSD made some changes that I don't have a diagram for. I figure the best place to start is to focus on that which is not connected to anything. I don't have a wiring diagram laid out like the harnesses so the copious use of brown and dark blue/green/etc by Dodge makes finding the purpose of loose connections difficult at best.

See the attached photos for pics relating to some questions I have for those familiar with the wiring on these.

A) The wiring diagram shows just a green w/ red tracer to the horns (sometimes listed as dk green only) but on mine, it's both to one horn and there is a brown wire sitting there with no connection. Anyone know where this brown one is supposed to go?
B) There is a second brown wire with an angled cap connector near the horns and alternator with no obvious connection mate.
C) There is a yellow wire (pay no attention to the VR upside down, the screws stripped out the holes so I need to get oversized screws -- It was grounded for testing) back by the distributor which *may* to lead back to the starter relay (pic available). The windshield wipers work so it's not that yellow wire so what else it would be escapes me.

I am hoping someone with more experience with these cars sees something obvious that I am missing. I know this is a bad first post but I bought a project and as I said, I am diagnosing this on my own and just looking for pointers, not someone to "do it for me" end to end. Diagnostic tips and any words of wisdom related to this would be much appreciated.

NB: I do not know how much of the parts on the engine came in with the recent rebuild (ie; carbs, etc except the edlebrock coil looks very new.

 

[terraformer]

Some updated info:

Continuity test, with ignition off, from BATT to positive on battery with the negative battery lead off was positive. Continuity exists.
With Ignition on, engine off, the wires to the field tabs on the alternator are "hot" (7 and 10 v respective) and the wire to the VR is hot, both leads (don't remember voltage). This seems to suggest the VR is not grounded or bad. Can it be anything else?

 

[terraformer]

Do challengers have alternator fuses? I can't find any fuse on the wiring diagram but I figured I would ask.

 

[terraformer]

Well, don't know if any one is even following this saga but alas, the reason why I couldn't find anything wrong was because the wiring was fine. The first two replacement VRs were bad. The third time is the charm. I took it out for a spin today. I also grounded the crap out of the VR while I was at it and changed the screws to modern sheet metal auto screws (which was made possible because of the new grounding wire).

 

[JDcuda]

Had the same problem with my first two VRs. dont know what is up with that..

 

[Chryco Psycho]

the seal behind the VR opens up & allows moisture behind & will kill the VR very quickly