Thread: electric short

how old is the battery, and if you dont have a onboard charger get one and plug it in all the time

A battery switch would only mask the problem. You have an undesirable current drain that needs to be isolated and fixed.

If I remember right(?) if its a LOW unit and u have a stand a lone GPS antenna that antenna is always pulling some power unless u have a separate switch to turn off its power in the NMEA 2k wiring. This switch would be placed between the power source and the fuse , that being before the power line is plugged into the NMEA 2k system. The GPs antenna does not get its power from the screen unit.

These are brand new Humminbird units but this was happening before install of new units. Both units are plugged into circuit boards(one under the dash & one under the bow). When the units are unplugged the test light still works until the fuse is pulled. Meaning the units have nothing to do with the problem, so it's got to be the circuit board? Right? I know a 4 bank charger would keep all 3 trolling batteries and the cranking battery charged but I would like to fix the problem if I can.

The cranking battery is a Blue Top Marine Dual purpose AGM 800 CCA. This battery has been complety dead about 3 times over the last 6 months but has always been recharged back. I have left a 10 amp charger on it over night just to make sure it is up. It will last about 1 1/2 days and then battery is about dead. won't crank, trim will not work locators will not work. During a day of fishing in the late afternoon when I start the the engine the locators will shut down telling me that the battery is low. Charge it up that night and it will run about 1 1/2 days. Need to find the problem. Even if the battery is getting old I still have a short. Thanks

Your battery needs to be load tested. If you have another battery try and see if it performs better. Humminbird electronics will only have a 3 amp draw.

Okay, Your power cord to each Humminbird is connected to a circuit board. What exactly are these circuit boards, are they basically just a terminal strip with no fuses? Where is this fuse you pull and the draw stops? On my boat, there is a fuse panel/circuit board under the dash. There are terminals to hook up equipment and each one is fused. If you have a terminal strip under the dash or thereabouts which 1 H/B is hooked to, and another terminal strip on the bow that the other H/B is hooked to, you need to start a process of elimination. Find out where the bow terminal strip is getting it's power. Disconnect that and see if you are still getting a draw. If so, look to the terminal strip for the console H/B and disconnect the power to it. Do you happen to have a radio on the boat? Some of those have a constant power draw.

[QUOTE=Shellback;2638537]Okay, . Do you happen to have a radio on the boat? Some of those have a constant power draw.[/QUOTE

Good thinkin, or even a clock will draw. Sometimes a certain battery charger when hooked up will draw a little when not plugged in to AC. How bright is the test light? Very dim or fully lit?