Thread: got a power drain

Unplug or pull fuses on everything connected and then put fuses back one at a time and see if voltage drops then plug up connections and see if voltage drops. I don’t know of a simple or easy way to find something like this. By pulling fuses and unplugging connections at least you hopefully can narrow it down and then start looking at what is connected to further trouble shoot. I have a dedicated accessory battery just to minimize the risk of a dead cranking battery. I would think that any short should shoot a fuse or trip a circuit breaker.

If you have an Ohm meter and are comfortable using it, here is what I would do. First, I would isolate where the draw is coming from. To do this, disconnect everything from positive terminal on the crank batter. Connect the black lead from your ohm meter to the positive terminal. Make sure ohm meter is set to measure current, and put it on it's "lowest" setting - so that you can see a very small current draw. Then, one by one, connect the loads (Helix 10, 7, etc) to the red terminal of the ohm meter. If everything is off, you should see no drain across the meter. If the load center is the issue, do as Catton indicated to isolate which circuit is "leaking". You actually can pull the fuses, and use the ohm meter as the fuse - you can then see how big of a draw it's pulling. From there, you will have to determine what all is on that circuit to then find the culprit! Good Luck!!

Connect a known good digital meter to the cranking battery set to "Volts". Note how in your current condition, the volts are dropping. Remove items one at a time until the volt drop stops - in fact, you should note the volts will actually start going up when you find the culprit. I have taught this process for many years. If you have fuses, they may be pulled one at a time to find the affected circuit. It's actually quite simple.
I advise you once this problem is corrected to install battery disconnect switches for each battery. Install the disconnects on the negative side of each battery. My switches stay off up until I launch, and are off again after I load the boat to go home and have the motor stabilized. My chargers connect thru fuse protected separate pig tails straight to the batteries and NOT thru the disconnects. All else goes thru the disconnects.

Hello: I would do as the grand pooh bah said but if you have an automatic bilge pump I would also connect it directly to the battery including a fuse. Good Luck. O - R