losing voltage

[fisheymikey]

i have a issue in regards of losing power...

even with a switch or had both batteries connected together im getting lose of voltage.

this is happening when the boat is not running.

im assuming is somewhere between the ignition switch or somewhere on the motor.

I guess my question is if the engine is off where would there be a consumption of power without it running

all my electronics i.e. pump, radio, gps are on independent switch board so that is not an option

thanks

mike

 

[glenn property of pam]

losing voltage? what do you classify as losing voltage. Do you mean that the voltage gauge drops or do you mean that the batteries are draining when the boat is not in use. Fully charged the batteries should be at 12.6v when the motor is not running. The batteries may be higher when the engine is switched off but they will drop to the 12.6v reading after a few minutes.
Now if the voltage at the console is lower that the voltage at the batteries then that is a different problem and is classed as voltage drop.

 

[pnwboat]

Kind of hard to say without understanding how your boat is wired. Are you saying that you can disconnect all of your accessories and you're still experiencing a drain on your batteries? Are you checking the current draw with a meter, or just seeing the batteries go dead after a while?

 

[Jiggz]

As the two previous questions, you need to detail what you mean by losing voltage? Is it like in a matter of 2~5 days or 2~5 months? If all accessories are on a separate switch or distribution wire, then there could only be two things that can cause the battery drain, the motor and the battery itself. It is easy to isolate which one is actually doing the drain, disconnect everything from the battery terminal and wait for a few days, if the battery drains still you know which one. If they do not drain at all, then something in the motor is miswired or shorted either in its own ckt or to ground.

 

[fisheymikey]

that exactly it... the batteries drain after a few days.. and it not the battery. were would I start to start isolating the problem...

 

[Jiggz]

Do you know for sure it is not the battery? Then it must be the motor. First, isolate one of the batteries by disconnecting both terminals. Second, isolate all accessories. Third, using a multimeter and its DC current measuring function (usually max is 10 amps), place it in series between the positive terminal of the battery and the big red cable connecting to the starter solenoid (mind the polarity of the probes). If there is any current drain it will be indicated in the multimeter. You might need medium size alligator clips to keep the multimeter connected. While connected you can try wiggling some of the wires around, BUT DO NOT TURN ON THE ENGINE OR WORSE YET START IT AS THIS WILL DAMAGE YOUR MULTIMETER.

If after the initial connection of the multimeter it read current and then went back to zero, it is an indication the current drain is too high and could have blown the meter's fuse.

 

[fisheymikey]

so if I understand correctly I put the battery close to engine ground the battery to the engine then use put my multimeter to dva current ( yes it is 10amps) connect black lead to positive then the red lead to the starter solenoid. then wiggle things around. what should I be looking for... a sudden drop?

 

[glenn property of pam]

The test is for amps which is the flow of electricity not volts which is the pressure of electricity so there is no wiggling wires or anything like that.
if its a outboard engine then just unhook the positive lead from the battery. set meter to dc amps. move leads on meter to the correct hole to measure amps. Then put the red lead to the battery positive post and the black lead to the cable you removed from the battery positive post,
The reading should be 0.0 but may read 0.01 or less as you have a radio that will be using power to supply its memory function. If you get a reading of 0.0 then turn on the bow light and the reading should change to maybe 1 amp (this shows that the meter is working correctly). If you get a reading higher than 0.1 pull fuses until the reading goes back down then see what item you had to pull the fuses from.
notes: on a inboard motor check that the alternator is cold to the touch. If the alternator is warm/hot and the motor has not been run for a while this may be your amp drain. Pull the sense wire from the alternator then do the above test. There is a chance that the amp draw from the alternator may be higher than 10 amps if it has a bad diode which may blow the fuse In the meter when tested.

 

[MickLovin]

If you are getting a voltage drop with the ignition off, it is more than likely a bad battery or a shorted wire. I have also seen ignition switches fail on the start to on position, keeping the starter motor running but not engaged causing a voltage drop.