Is any one running dual batteries in their truck. i installed mine and i am going to use a dual battery isolator. I have an isolator already but it causes my battery light to come on. I have determined that you need an isolator with 4 post connectors, where the 4th terminal is used for some wire sensor wire from the alternator

Has anyone used a battery isolator? what models have worked. any ideas? i know its a confusing and boring topic.