Thank you for the response. This is where I am a little confused. On the vehicle dash board (ford e350) it has a switch that says "battery" Dual-MUM. Left (when pushed)is Dual and right MOM. I have the vehicle manual and the generator manual. They talk about a Battery Mode Switch. Not sure if this is what they are referring too, but I believe so. It says that if it is started while both batteries are connected, it could cause damage to the automotive alternator. Not sure what way the switch should be pushed?
