It’s about the charging to the battery from the alternator.  

13.9 comes to the battery from the alt.
but when that wire is connected to the battery, it shows only 12.5 and slowly less and less as the engine is running until 11.95. 

one funny thing I found; when I check the continuity of the other red wire (not the one from the alt.)  to the ground, it beeps for a second, no more.  

I don’t know what to check, where the juice is leaking to.  We have gone through two alternators, three new batteries.

I even made a new set of wires from the alt. to the battery direct.  Not sure, it’s the right thing.  Looking in the Bentley it seems to be direct, but I can be ‘wong’ again.  The alt. wires go into a loom and I don’t know if they do anything else other than coming out at the battery.

Anyone’s help would be appreciated.

Zoltan