Tracking a Short???

[Neighbor_guy]

Cut right to the chase here....

I recently purchased an older bass boat and while I am enjoying it ( a lot!!! ) I have run into an issue. I am draining my starting battery while it is not in use. Now seeing as EVERYTHING other than the trolling motor and the radio run to the starting batery I need to know where to start to find this short. Anyone have a check list????

Starter, trim motor, livewell pumps (2), bilge pump, dash panel, what else? I am tired of having to pull the (+) lead off the battery when I am fishing so I can be sure the motor starts. But something is drawing power in a big way and I would like to resolve it.

HELP!!!

[jeffreyd]

get a cheap ammeter and see how much it is draining while just sitting. if you can disconnect individual items from the battery or pull fuses for each item you can watch the meter to see which one is pulling the most drain. Could be the start solenoid. One other thing you should not do is pull the positive wire off the battery. You cause a spike in the system when you are doing this. Always disconnect the ground or negative cable to keep this from happening, this is on any type of vehicle.

[broken_line]

if it was a short it would have bunt your wires right up.. im guessing a faulty gauge or something along the lines of that.. is the battery newer??

[Neighbor_guy]

The battery is brand new. It drained a new starting/cranking battery so dead it will no longer hold a charge because it was left it hooked up by the previose owner for 1 week. I put a new deep cycle/cranking battery on it because I knew there was a drain, but it will still depleate the battery to the point the starter will not engage if the leads are kept on for as little as 4 hours.

Mabe "short" is the wrong word. There is a "powerfull draw" of power when my boat is not running that drains my starting battery dead.

[broken_line]

thats really wierd! leave it on for 2 hours or so and start feeling the wires, electronics, around the motor and anything that hooks up up to that battery.. something should be hot because that energy if not moveing anything has to be converted into something like heat..

[Ralph Wiggum]

It's draining a deep cycle in 4 hours? Wow, something is really drawing some amps!

[marine_man]

What brand motor do you have?

The best way I've found is to pull all the connections off the positive side of the battery. One connection at a time, touch the positive wire to the battery post. If it sparks, it's drawing current. You'll need to chase it down from there.

The other thing you can do is get a test light and touch the test light to the battery post, and connect the other end to each terminal - the brighter the test light, the more current draw that circuit is pulling.

marine_man

[Neighbor_guy]

I have a 1984 115 Mariner on it. The previos owner put a "system shut off" switch on it that all of the positive lines run to. Kind of a rotating togle switch. I am going to have to pull the switch apart to get to the lines, but I dont know what else to do. Mabe tomarrow, I had planed on it today, but I dont have anyplace dry to work on it.

Oh the joys of boat ownership. I am starting to miss the old tin can boat and the simple home made electrical system I had in it.

[broken_line]

B.O.A.T.

Broke

Once more

Another

Thousand

__this was a nother FMers saying that stuck with me_______________________

[marine_man]

The previos owner put a "system shut off" switch on it that all of the positive lines run to.

Sounds like the previous owner had battery issues as well...

marine_man

[Surface Tension]

I was thinking a bad rectifier but that won't drain a battery that fast. Now if your starting battery does not have enough CC amps to begin with, then add a drain, I could see how it wouldn't turn over. Lets add dirty or loose connections in there. Maybe a starter and or solenoid that is on its way out to that slow drain. So after 4 hours have you truly drained the battery or is it just a little weak with a few other problems mixed in. Checking the voltage at the battery will tell you for sure.

Just so we have this right. Even with the shut off switch your draining the battery?

Is this switch's intended use made as a battery isolator or is it something the previous owner rigged up? What is it mounted to? Aluminum? I'd make sure it not getting grounded to the boat.

What all is coming out of the switch. Just the + cable to the outboard or are all the accessories there as well? If its the later then it shouldn't be draining unless something is wrong with the switch. If the switch is good and just the outboard is hooked to it then you have something going on with the accessories. I hope you have an in-line fuse close to the battery on the + accessory cable. That should run to a fuse block or panel with breakers. It'll be a process of elimination there.

[marine_man]

I was thinking a bad rectifier

I was as well... until he said it was a Merc... usually Johnson / Evinrudes are the only ones that will do that when the rectifier is shot.

marine_man

[jeffreyd]

charge the battery, leave it sit with everything hooked up, without starting the engine, remove the cover and feel around for anything that might be warm. It could indicate a leak that is causing the drain. We do this on fire truck altenators, if we can ever let them sit that long. It is a good way to feel for a leaking diode or other issue.