Alternator Pulsing

Great diagnostic advie all around. The motor has the ground strap from the battery to the drivers side iron cylinder head, whereas the ground strap from the motor to the firewall attaches to the aluminum intake manifold. While I doubt it matters, I will move the ground strap to the pass side cylinder head.

I will also check to see if it pulses at the alternator positive output stud.

It does not pulse all of the time, and can be loaded or unloaded. I noticed that when first started, the ammeter swings to high charge,, and as it backs down to closer to center, it begins the pulsing/switching behavior. It can be seen in the headlights (that are relay equipped) and in the dash and interior lights.