D10A and D10EMS differing voltages

madb1rd

Member
Joined
Dec 8, 2007
Messages
50
Question...
I seem to be having a strange voltage ghost going on.
The EMS is saying I have low voltage at 12.1-13.4, which is lower than the regulator setting of 13.68v. But my load shunt from the generator is reading 14-20 amps charging from the alternator.

And the part I'm not sure about is when I switch the D10A EFIS screen to read EMS data it shows the buss voltage to be about 1 volt higher than what the EMS says. All other data on both screens are the same. With the screen share like this does the D10A supplant its own voltage reading into its display?

I realize I also have to troubleshoot why the EMS V is reading low... and verify if the alternator is in fact charging correctly. But I was surprised by the different V readings between unit displays.

Thanks
 

Rhino

Well-Known Member
Joined
Jul 20, 2009
Messages
1,615
It may be where they're reading the voltage from. You'll get small variations in voltage depending on where in the electrical system you measure it, especially with stuff turned on. If they read from the same point, I'd suspect wiring or the D10 units themselves.
 

airguy

Well-Known Member
Joined
Nov 10, 2008
Messages
1,105
Location
Gods Country - west Texas
You've got some voltage drops (likely poor connections) some where in your system, and you are sensing voltage at different points for different devices. Time for wire chasing and connection cleanup, that's always fun.
 
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