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dick seiders

Well Known Member
Has anyone else experienced this Dynon feature disappearing on them? (on main page 15 gal and less). After three years no less. If so, what makes it go away and can it be found somewhere in the caverns of the Dynon? Or does it mean a total repeat of the messy (and hazardous) calibration process as described in the Dynon Manual?
Dick Seiders 120093
 
Dick,
Have you recently been into your Dynon menus? It is real easy to mistakenly turn off a display.
Look in the EMS menu/MORE/SETUP/SENSOR/FUEL LEVEL and check that the display is ON.
Another check is the GLOBAL setup menu. Have you recently made a change in this menu? It may be possible to set the number of fuel tanks to "0".

Tony
 
Tony, thanks. I checked Dynon and all appears in order. (No.1 main tank and it is turned on etc.). I did an ohmeter check on the sending unit in the tank (sending lead disconnected) and got no reading of resistance. I am not certain , but suspect this means sending unit in the tank is defective does it not? In thinking back to the first hint of a problem several wks ago the quantity shown remaining on page 1 did fluctuate between 7 and 2 gals while flying. The next time I went up the reading was zero and has been since.
Dick Seiders
 
BE SURE TO CHECK THE GROUND - -

several have had problems with that. Did you test with the negative on the airplane frame, or tank itself ?
 
There are two different fuel remaining values.

Fuel remaining as calculated by the fuel computer, and fuel level (remaining) displayed by the fuel level gauge.

If the problem is being caused by the fuel level sender it would have to be effecting both of these.


If you do not measure any resistance from the sender to airframe ground, check for good ground continuity between the mounting flange of the sender, and airframe ground.
 
To check the sender...

Measure the resistance between the sender center terminal and a point on the sender flange. Be sure to scrap a bare place on the flange.
CTT_3486-M.jpg

The sender resistance varies between 30 ohms and 240 ohms. You should get a resistance between these values if the sender is working. If so then as the others say, check for the bad ground between the sender flange and the airframe. Others have had to run a ground wire from the sender flange to the airframe.

Tony
 
rvbuilder2002 said:
......If the problem is being caused by the fuel level sender it would have to be effecting both of these.......
Click to expand...

Scott, I don't see how the sender in the tank could be affecting the computer calculations that are based, as far as I know, on fuel flow - essentially subtracting fuel available from the value set into the Dynon.

Most likely scenario is bad ground. I had to add a wire.
 
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BigJohn said:
Scott, I don't see how the sender in the tank could be affecting the computer calculations that are based, as far as I know, on fuel flow - essentially subtracting fuel available from the value set into the Dynon.

Most likely scenario is bad ground. I had to add a wire.
Click to expand...

You are correct... Sorry, I was tired.
What I was trying to say is it wasn't entirely clear to me which display he was saying didn't read correctly.
In pilot speak...
Fuel remaining is usually talking about what the fuel computer says is left in the tank.
Fuel level is what the fuel gauge says is in the tank.
 
Thanks to all replies. I tested the ohms between the sensor wire center connection and the mtg plate, and there was no readout. Connecting leads to mtg plate and aircraft ground does show continuity. So I presume this is clear evidence of the tank sending arm failure to operate. Comments? Thanks.
Dick Seiders 120093
PS per Scotts definition it is the fuel level remaining in the tank I am referring to.
 
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The screw where you connect the positive lead to the sending unit has a very small solder point on the inside of the mounting plate. If when you installed the lead you turned the screw to tightly it is easy to break the solder point. Have you by any chance removed the tank lately?:rolleyes:

355f84cacaa8f2871b567df66745365d_zpsdcf127f3.jpg
 
John, that's an interesting possibility, but I do not tighten the screw so m,uch as just snugging it. Pulled tank last time in Sept. of 2012. Failure occurred just a few weeks ago. Thanks for the feedback and when I pull the fuel level arm in Oct. I will check the solder joint to see.
Dick Seiders
 
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