Yea, I understand that, but regarding the second battery, a lead comes from the split charger, to the second battery, and if the van runs, it thus sends a charge to the second battery, the wire basically connects to the pump aswell. So doesn't the charge go to your pump instead of the battery whilst running the engine?
It looked like you said, from split charger it goes to the second battery, charging the battery, and then the battery powers the pump, but how is that possible if your using one battery pole, and two wires connecting to that. (One to pump, and one from the split charger to the pole)
Sorry Roy, perhaps I can't explain it properly.