I'm currently fabricating a dual battery system for my truck. I have welded all the brakets for the new tray and fuse box (for my offroad lights) and have a second battery. I was wondering which wire that I have to splice into before going to the isolator. There are many wires coming out of the alternator and I have lost the instructions that came with the isolator to tell me which one. The rest of the wiring should be a walk in the park.
Oh ya, I've got a Ford inline six cyl.