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BF50 Battery drain

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Yenrec

New member
I traced my battery drain issues to the main leads coming from the motor. The multimeter reads over 12 volts, just under what it reads when i touch the plain battery posts alone. None of the other leads attached to the battery read any current draw except for leads to motor wiring. I pulled some fuses in the motor case itself and finally when i removed the 15 amp fuse closest to the boat itself the current draw disappeared. Attached are two pictures showing where I'm talking about. Any idea how i can solve this issue and why is it drawing so much power when nothing is turned on?
 
I am a little confused....you mentioned current draw but also mentioned measuring voltage.

Which did you measure?

If you were actually measuring the current, as you have your amp meter connected, pull apart the bullet connectors on the white lead in the crossconnect area under the plastic cover on the side of the motor. If the current draw goes to zero, then you most likely have a bad diode in your regulator.

Mike
 
I am unsure which I actually measured. I took all the positive wires off of the battery post and screwed the positive lead from my multimeter onto the battery post. The multimeter was set on the 20 DCV setting and I touched the negative multimeter lead to the positive cable for motor wiring and it read over 12.0
 
I just did some more digging around on the motor, when i unplugged the cream wire that plugs into the white with yellow marking(pigtails off another plug) multimeter quit reading any draw. Here are a few pictures showing what I'm talking about. Looks like cream colored wire goes into piece with the cooling fins on it seen in picture below. Also took a picture of draw that multimeter was reading.




 
You are not measuring the draw, you are just measuring the voltage at that point....and there should be voltage at that point.

I hope I can explain....so here goes.

Think of the wires as water pipes and you have water coming in from the street.

The water pressure is like the voltage measurement. The amount of water used when you turn on the faucet is like the current flow. If there is a leak in a faucet, there is a small water flow...like a current "draw".

The water supply coming into your house is like the battery. If it was coming from a cistern that has a fixed amount of water, your leaky faucet will eventually empty the cistern. Just like the current draw is draining your battery.

That being said, with the meter connected the way it is and set at voltage, you are measuring the voltage (water pressure). To check the current drawn, you have to move the red lead where it plugs into your meter to the hole just above where it is plugged in the says 10A.

You also need to move your meter dial setting to the 10A setting. I am picking the highest setting you have since you do not know how much current you are drawing from your battery, so I picked the largest you can measure to protect the meter. It may or may not be fused inside. Since these meters are given away at Harbor Freight, I am sure corners were cut to make them so inexpensive.

Ok...we now have the meter set up for current measurement.

Now .....be sure that all devices in the boat are turned off...do not start your motor or turn anything on since it could cause too much current for your meter to handle.

It is possible that your draw is coming from somewhere else in your boat that the motor....so I would start at the battery.

Disconnect all the leads connected to the positive side of the battery having issues.

Then one by one ...touch one of the leads of the meter to positive battery terminal and the other lead to each of the wires that you took off....one by one. If the meter has any reading at all on a lead, that is the indication that there is a current "draw"....and it tells you how much it is drawing.

Depending on the lead that has the draw....then you start exploring what that lead provides power to.

If you find the lead is to the engine, then you can go back to the white leads that you took apart. Pull the leads apart and connect one lead from the meter to one white lead and the other to the other white lead...and see what you have.

DO NOT CONNECT EITHER LEAD TO A GROUND, THE POWERHEAD, OR THE NEGATIVE SIDE OF THE BATTERY WHEN THE METER IS SET TO CURRENT.....IT WILL BLOW THE METER.

Try that, and let's see what you get.

If you find that the engine is not the problem, most likely something at the dash is draining the battery. The most typical is the radio memory...it does not draw much, maybe 10 - 15 ma, but it will drain a battery over time if it is not connected through a switch.

You can easily test each circuit at the fuse panel but pulling each fuse, one at a time and connecting your meter (set for current reading) across the contacts of the fuse holder that you removed the fuse from. Basically, you are putting your meter in place of the fuse. Again...DO NOT TURN ANYTHING ON OR TRY TO START YOU MOTOR. Also, do not change the setting of the meter back to voltage (DVC) and do this....it will blow your meter.

Don't worry about the reading being positive or negative for this exercise, it will be one or the other.

I hope that makes sense.

Mike
 
Thanks. It was the best I could do at midnight.

One thing I forgot. The easiest way to measure a current draw is by using a clamp on DC amp meter. You just clamp it over whatever wire that you are questioning and it reads it.....and no worries of blowing the meter and no having to take things apart. Something like this one. http://www.sears.com/craftsman-digital-clamp-on-ammeter/p-03482369000P

But here, we are going with what you have to work with and it should work fine.

Mike
 
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