As suggested I removed the Bat wire from the regulator and found I lost no charge overnight. Then took a look at the cutout relay and the points were stuck. I freed them up and polished the contacts with a piece of cardboard. No lost charge overnight. This appears to have solved the problem but I will monitor those contacts for a while to be sure. I may even stock a spare regulator for that truck.
Apparently this discharge situation is very bad for generators as the the points are trying to turn the generator into a motor with battery power. Thanks Shark, Tim and Jerry for your advice on this matter.
