Lowrance FUEL FLOW sesnsor registering flow when engine is OFF

[Troutboy NZ]

I?m having problems with my Lowrance EP-60r fuel flow sensor,the sensor works well, but the problem is since the NMEA network is wired as ?always on? from the master battery switch, in the rough while anchored, the flow sensor is reading flows of around 0 ? 2l/ph when the engine is not even on as I presume the small turbine is sensitive to boat movement and wave action. This is throwing out the accuracy a lot.

I have wired to the ignition ON wire from the control box thinking it will only read flow rates with the engine running which is ideal, and all works as it should...

BUT...

When I turn the ignition OFF, the 'fuel remaining' information displayed on the Lowrance LMS522ci-gps head unit reverts back the to the 'tank fill' volume of 25l showing no fuel used? Not sure why it's doing this, not retaining the information, when it did so when permanetly connect to the master battery switch when off and on as previous. Any suggestions? Thanks

 

[HONKER1]

Re: Lowrance FUEL FLOW sesnsor registering flow when engine is OFF

I've been watching this thread, hoping some of the more knowledgeable member would come up with a explanation. I also have noticed that my Lowrance 5300 will show fuel being used, even when the motor isn't running, but I haven't used it enough to determine if the accuracy is affected or to what extent.
I didn't hook mine to the ignition as you did, but did put a on/off switch in the the power to the NMEA side off the unit. I have noticed the same findings as you did. With the switch on, I get a reading of how much fuel is still in the tank, when the switch is turned off it will revert back to the "Tank Fill" volume.
The only explanation I can come up with is that the "Tank Fill" setup is part of the 5300c iGPS, and the EP-60R Fuel Flow is part of the NMEA setup. No power = No reading.
This is similiar (and I don't understand why Lowrance made it this way) that the GPS readings can't be transmitted to the NMEA network. Marketing to sell more LGC modules???