So I found the blk/wht wire from the engine harness going to C-7.  I checked for voltage on the output side of C-7 and there wasn't any, with the ig switch on.  I cut the wire and spliced it directly to the ignition switch blk/wht wire.  Now in the ON position I have 12v at the blk/wht at the VR and just under 11v at the F terminal on the alternator.  I will try starting it over the weekend and advise if this has resolved the issue.

If it doesn't it means you have some more wiring bugs to squash. Make sure you still have good voltage to ground on the black/white at the ballast resistor.

So I started it and checked the voltage at the F terminal.  It was 5.5-6v.  The voltage at the blk/wht wire going in to the VR was 12v.  Motor off and IG switch ON at F terminal 11.9v.  Suggestions?

@SteveJ This looks like a corroded or broken harness. What are the chances of having a bad ground connection?

4 hours ago, Dolfinz said:

So I started it and checked the voltage at the F terminal.  It was 5.5-6v.  The voltage at the blk/wht wire going in to the VR was 12v.  Motor off and IG switch ON at F terminal 11.9v.  Suggestions?

Start the engine and see what the voltage at the battery is with the engine running.

2 hours ago, Yarb said:

@SteveJ This looks like a corroded or broken harness. What are the chances of having a bad ground connection?

It wouldn't hurt to see what that looks like. @Dolfinz - Could you take a photo of the negative terminal of the battery, the end of the battery cable at the starter and where the smaller wire attaches at the firewall? Bad grounds can cause a lot of frustration.

2 hours ago, SteveJ said:

Bad grounds can cause a lot of frustration.

I always add a ground or two just to be sure.

Please see attached.

Yep, that's the expected level of Arizona corrosion. 😉 Did you try running it and checking the voltage at the battery while it's running?

I finally had a chance to check the voltage at the battery when running.  It was between 13.5 and 13.7v.  I assume this is sufficient even though the voltage is so low at the F terminal on the alternator?

The output is on the low side. What was the RPM for that voltage? What is the voltage at 2000 RPM?

The original RPM was 1000 at 2000 the voltage is 14.5v.  Is that acceptable?

14.5 is right on the money.