I checked the FAQ and found a thread that was similar, but not exactly the problem I have. One of my banks in my Cul-M-Rite will not turn on when plugged in. Brand new issue, just charged all three batteries on Saturday after I got off the water. I am no where near electrically proficient so please barney style any responses. I did everything in that other thread, unplugged the TM, took the TM lead off, switched leads around, no change. There is a black thing on the negative lead which looks like it houses a fuse, but the rubber grommet around it is sealed tight, so that may be an issue, but I dont know. 2004 boat by the way. Thanks in advance, Chaz- Chaz