So the head grounds to the body and then somewhere the battery is connected to the body? If that's correct, how about skipping the body or adding a dedicated head to battery line?All power grounds go to the head and then to the body behind the battery with the exception of some relays located where the PM was.
Also how much load does the load pro apply? I read one place that it was only 1/2 amp - is that enough? How I test grounds for O2/Wideband gages is that the reading should not change when I turn the headlights on and off.