Mystery power drain

[Beachbummer]

Thanks. The radio Is fully switched, so when the dash switch cuts power to it, off there should be no drain possible, but I'll keep checking.

I did notice as soon as you provide current the current jumps to. 16 and after a few seconds it drops to .03, so as if the ECU or something else wakes up and uses a little power, then shuts off and something parasitic is draining my 30ma.


I have added a few relays (for an extra horn and for the extra bilge pumps) years ago. and I have heard when they go bad they can possibly not open fully and can cause parasitic drains.

Thanks again for your ideas!!

 

[FSH 210 Sport]

Thanks. The radio Is fully switched, so when the dash switch cuts power to it, off there should be no drain possible, but I'll keep checking.

I did notice as soon as you provide current the current jumps to. 016 and after a few seconds it drops to .03, so as if the ECU or something else wakes up and uses a little power, then shuts off and something parasitic is draining my 30ma.


I have added a few relays (for an extra horn and for the extra bilge pumps) years ago. and I have heard when they go bad they can possibly not open fully and can cause parasitic drains.

Thanks again for your ideas!!

So when you provide voltage the current “jumps” to .016 then drops to .030? .016 is less than .030…

 

[Beachbummer]

So when you provide voltage the current “jumps” to .016 then drops to .030? .016 is less than .030…

Sorry... Extra zero... Jumps to 0.16 for a few seconds, then down to .03.

I corrected it above also. Thanks!

 

[Beachbummer]

I made an investing discovery today but i have not yet entirely figured it out, and I ran out of time.

I thought it was this added relay since the drain disappeared when I removed the ground from the relay. Strangely it also disappears when the ground is removed from the bilge alarm beeper. (But the led does not cause a drain)

I'm stumped because the float works and there should be no ground present when the bilge float is not triggered.

I think now that I know it's near here I should be able to better find it... But something is not as I think it is.

This is the intended wiring, but the behavior does not match. Something else bringing current/ground while the float is not active? Very strange. I'll keep you posted but I welcome your ideas. Thanks!!!

 

[Joatmon]

Questions. Is the relay a transistor MOSFET or a mechanical coil relay (ice cube)? The schematic tells me it is a coil relay but just checking. You are checking the amperage in-line in the circuit with a multimeter right? Can you bypass the alarm beeper/alarm lamp and see it you have a power draw?

 

[Beachbummer]

Coil type.

The draw disappears when i disconnect the alarm. I have no clue how it's drawing if the float switch is off but it is.

I will hopefully get a chance to troubleshoot more next week.

 

[Beachbummer]

Weirdly there is also an LED/lamp that does not illuminate except when the float is triggered. Something must not be what it seems. I thought at first the relay might be bad so I replaced it, but identical behavior after replacement.

 

[Joatmon]

I assume the LED that lights when the float is closed is the alarm/lamp LED. For some reason the alarm/lamp may be leaking to the ice cube relay coil. Not enough to pull in the relay contact but enough to see a parasitic draw. If the alarm buzzer and LED are one unit perhaps change it especially since you have narrowed it down to being the source.

 

[Beachbummer]

The strangest thing is that the led is not illuminated, but disconnecting the buzzer removes the load. I can't tell where the ground is coming from. I'll investigate again next weekend hopefully and learn a little more.

 

[Beachbummer]

So I think i understand what's going on... The buzzer was consuming the power but the led was not... Between the bilge pump and the relay coil, and the fact I was switching the relay on a ground path, it seems power was traveling across the bilge pump and relay coils while everything was supposed to be de-energized, but positive and ground where present in the wrong directions. Ground wire to coil had positive past the coil, and the the positive wire had a ground path from the bilge pump.

I'll change this to be all positive switch common ground, and that should do it.

I did also but a dpst relay just in case.

 

[sunbyrned]

Thanks for keeping us posted!

 

[FSH 210 Sport]

So I think i understand what's going on... The buzzer was consuming the power but the led was not... Between the bilge pump and the relay coil, and the fact I was switching the relay on a ground path, it seems power was traveling across the bilge pump and relay coils while everything was supposed to be de-energized, but positive and ground where present in the wrong directions. Ground wire to coil had positive past the coil, and the the positive wire had a ground path from the bilge pump.

I'll change this to be all positive switch common ground, and that should do it.

I did also but a dpst relay just in case.

Feel better?

A good lesson for all! Always switch the positive not the negative

Thanks for closing the loop!