*$%!@ pulsing lights

["The Staub Family" <jstaub@domain.elided>]

I have a '79 Scout II and replaced the alternator a month ago. It was not
marked, but as far as I could tell it was a 2- wire Delco 63 Amp with
internal voltage regulator. At least the new one matched the old one in
appearance. Well, the new one charges the battery (also new) OK, but it
makes the lights pulse at medium to high speeds. This doesn't happen all the
time; in fact I've seen it go from steady to pulse or vice versa when I hit
a bump. I thought it was a loose wire inside the alternator, but I swapped
out the whole thing and the new one does it also. Can anyone help me track
down where the problem might be? It's realy bugging the sh** out of me, and
probably the people I drive behind as well. Thanks in advance for your
suggestions.