2000 Thor WindSport class A motor home on a Ford chassis. The Battery storage control box malfunctions. With the ignition key in the off position the Disconnect Coach switch will NOT connect the coach with the two auxilary batteries for the coach. If I turn the engine on this switch will supply power to the coach and sometimes if I turn the motor off and ignition switch in the auxilary position it will supply power to the coach but not always. Anyone had this problem or a solution to keep me out of the repair shop?