Donnie, thanks...there was voltage on the yellow wire so the regulator is defective.
This design is also used on Alfa 164 sedans and if the blower motor needs replacing it usually takes out the regulator with it. It probably overheats as the large heat sink attached has no air passing over it to cool
the regulator. Wonder how many other cars use that regulator as they are not rebuildable. List is over $210!