djjsc Report post Posted January 7, 2021 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. Share this post Link to post Share on other sites
kaypsmith Report post Posted January 7, 2021 (edited) Welcome to the forum! If the house batteries are 6 volts, then they should be in series as the bottom diagram shows. But if 12 volts, they must be parallel as the top diagram shows. Be sure that 12 volt batteries are parallel, if incorrectly wired the circuit will be 24 volts, 12+ 12 = 24. Most units from the coach builder were 2 - 6+6=12, golf cart batteries were commonly used because they have in most cases a greater amp/hour rating than 2 12 volts. Edited January 7, 2021 by kaypsmith Share this post Link to post Share on other sites