Originally Posted by Christopher Thwaites
One or 2 more questions. There is a placard on the radiator housing that states the electrical system is NOT de-energized by disconnecting one battery. However, when I disconnect one or the other battery by removing the positive terminal, I cannot start the engine. Is there current to the computer system but not the starting circuit in this scenario?
If I install a third battery in parallel will it have any adverse effect on the charging system?
According to the wiring diagram, disconnecting the underhood battery de-energizes the whole system. Disconnecting the frame mounted battery does not.
When you say you cannot start the engine, does it turn at all? Do the dash lights come on? Do the lights work? It should work normally when the frame mounted battery is taken off.
While the aux battery is in the power circuit when the key is on, it is out of the circuit when the key is off. And if it is taken out of the van, the van should run the same as a van without the aux battery.