Our recently purchased 1990 Southwind (GM P3500 chassis) had a charging issue when we picked up; so limped it home between boosting/charging fr car. In the process of diagnosing (fried alternator) dismantled a rats nest of battery wires/connections underhood forward of rad. Once alternator was swapped & everything reconnected/all systems working, had a battery cable left over. Started researching; GM chassis service manual shows coach batteries parallel connected, while the Southwind service manual shows coach batteries connected in series. WHICH is correct? FYI; haven't had any electrical issues since alternator swap/battery reconnect........ but am puzzled. Thanks in advance.
PS; 1st pic is the GM battery schematic; 2nd is fr the Southwind manual.
