Fuel Tank Gauge/Sensor

[skippydiesel]

As regulars will know, my Sonex has, in addition to a large in fuselage header (40L), wing tanks (30L).

 

The in fuselage, uses a RED Avionics, resistor type fuel sensor - excellent!

The wing tanks use the old style mechanical float on arm.

The left tank sensor is pretty good from empty to full.

The right tank sensor does not seem to work above 25L capacity. Its not bad from 0-25L, which is ok, as I always know what I have put in BUT it annoys me in such a new aircraft.

Both L&R will indicate empty when 4 L remain - good for 16min/4L - not that I want to test this out.

In the vain hope that the problem somehow related to a bad connection, I have checked all & found them to be good.

 

My feeling are;

 

• Live with/manage as is. No added cost, least effort and no pilot should rely on fuel gauges.
• Replace both wing tanks with RED Avionics type. Big job& costly, so would appreciate any less demanding suggestions

😈

[sfGnome]

This might be more work than it’s worth, but can you swap the sensors from one side to the other to see if that’s the issue? Also, is there any calibration on your gauges that might be awry?

[skippydiesel]

11 hours ago, sfGnome said:

This might be more work than it’s worth, but can you swap the sensors from one side to the other to see if that’s the issue? Also, is there any calibration on your gauges that might be awry?

Thanks for that.

Recalibration(FYI its a Dynon Skyview) has been tried & made no difference - the right tank sensor/read out performs with reasonable accuracy, when the tank gets down to about 25L (from full/30L).

A swap L-R has not been tried - This would be quite a demanding exercise . I think I would rather change to the RED Avionics type sensors, rather than swap sides.

In telling my story, I guess I was hoping someone out there had discovered a quick/easy fix.

😈

[sfGnome]

A possibly easier alternative (ground ops only) is to disconnect the wires at the two wing sensors and sling two temporary wires across the cabin to the opposite wings so that, electrically, the sensors are now connected as if you had swapped them. If the problem appears to move to the other side on your display, then it’s the sensor. If it doesn’t, then it’s somewhere in the rest of the system.  You wouldn’t want to purchase all new sensors and then find the problem was elsewhere (unless you really really want new sensors 😛).