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Join Date: Nov 2005
Location: Lancaster County, PA
Re: positive and negative leads
you have several questions across different threads, i'll try to address as much as I can here in one post.
5 hours running a fishfinder drained your battery, so you think you have a drain somewhere else. First off, is your battery constantly on a maintenance charge that was disconnected right before use of the boat? If not, how long before use was your battery fully charged? How old is this battery? You said brand new, was this your first time running with it? Was this battery the same capacity and type as the ones you have run in the other years when you had more time? Have you checked the water levels? Batteries self discharge over time. Also, many motors have a slow drain even when not running. Point being battery may not have been fully charged in the first place, and/or just does not have as much capacity as you had in the past.
There should be no inline fuses on your motor leads. Fuses have nothing to do with a power leak.
Regarding the different number of positive and negative leads, that is not abnormal. Maybe not perfect, but not really a problem. whatever uses the odd + wire is tapped into one of the other grounds some other place (I'd guess at the breaker box since you have one).
To find out what wires go where, you don't need to physically trace them back to their end point. Just make sure everything works. Then disconnect one of the + leads, and then turn everything on again. Whatever now DOESN'T work is powered by that + wire. Reconnect it, then repeat for the other + wires one at a time. I suggest labeling them once you know what they power. Then reconnect all the + wires, and do the same process for each of the ground wires. Again, label what they ground.
Once you know what wires power what, you can add up the draws to figure out what fuse size you should be using in the inline holders.
If you think you have a power drain, turn everything off. Then, disconnect all the + wires. You need an ammeter, not a voltmeter for this. Assuming you have a multimeter, set it up for dc current, milliamp range. Put one lead on the + contact of the battery. Touch the other lead to one of the disconnected + wires. With everything off, you should see 0 milliamps flowing. If you see a number greater than 0 with everything turned off, then you have a current leak on something powered by that wire. Repeat for each + wire. Since earlier, you labeled your wires indicating what they each power, if you find a draw on a wire with everything off, you know which items to look at.
How to best test to see which of the items on that circuit has a shut off power draw depends on what those items are and how they are wired.