Just to wrap up this thread, it turned out that I had mistakenly replaced the ground fuse with a 40 amp replacement used for the battery & tow vehicle instead of the 50 amp needed.
Thanks for everyone's input!
Whenever you find yourself on the side of the majority, it is time to pause and reflect.
If you find a source for 40 amp AGC fuses (the size for car fuse boxes, about 1 1/4"x 1/4" ) at a regular price let us know. I have tried auto parts and audio with no luck. The highest I can find is a 35. I am now using a auto reset breaker.
We have the larger size univolt fuses rated at 40 and 50 amp. We also have the MDM 40 fuses as well.
I had the same problem with my 69 as everything would work while plugged in to shore power but with the battery nothing would work. I found the ground side from the battery had a blown 40 amp fuse. Changed the fuse and all worked again. On my 69 both the pos and the neg side has 40 amp fuses in the fuse panel. I have since taken out the original type fuse panel and went to an audio install shop and bought maxi fuse type holders so the fuses are more easy tio come by.