Hi Everyone. I have just connected my Cyrix 120 as per the wiring diagram. When engine starts the cyrix operates fine and quickly closes to charge my Lithium 100ah Aux battery. But when Engine stops the Cyrix stays closed and my readings show a back flow from the Aux battery until the voltages are equal. ie the relay is not opening again to separate the two Batteries. I have reconnected carefully following the connection sequence but to no avail. Do I have a faulty unit or am I not understanding something ? Terminal 86 is connected to negative. But I am not using starter assist. Thanks for any help.