tach wiring and fuel calibration dynon

mbick7077 · #1 08-19-2011, 09:20 PM

Had the first start with my RV 9A.

The tach is not working. I though that I followed the wiring instructions from dynon 120. There are two tach leads from the right mag. Wired 1 to the right RPM from the wiring harness and the other 1 to a ground? nothing? Help?

Having a problem with the calibration on the fuel tanks. Am using a resistive type of float sensor. started with an empty tank and then added 2 gallons "add" button repeat. The last 4 to 6 gallons the screen indicated "did you add fuel? press yes?" It appears the float was at the top of the tank and could not go any higher? Good? Bad? Ugly? OK?

thanks

Mel from Colorado

cfiidon · #2 08-20-2011, 06:55 AM

Mel,

It appears the wiring instructions for the D120 are the same as my D180:

Wire from the p-lead (usually at the mag switch, thru a resistor (supplied) and then to either pin 32 (left) or 33 (right).

See page 3-4 of your installation manual... there's also a diagram.

Nothing should go to ground. If I understand that you connected both wires to your right mag and grounded one then your engine is probably running only on the left mag.

Don

AllThumbs · #3 08-20-2011, 08:42 AM

Hi Mel,

Find out if your two tach leads are from a tach sensor screwed into the mag (not a p-lead tap which would be only one wire). If so, you probably need a 22k 1/4 watt pull-up resistor across the two tach leads.

The tach sensor may look like this: http://www.aircraftspruce.com/catalo...ltachslick.php

mike newall · #4 08-20-2011, 06:25 PM

The fuel gauge will only show the last 12 to 14 gallons because you are right, once the float touches the top of the tank it won't show any more.

I think we just said yes at each occasion until the calibration was complete.

Our tank gauges work fine for the lower bits which is really what you are interested in I guess

mbick7077 · #5 08-20-2011, 07:59 PM

I have two wires coming from the right mag They are labeled tach leads. How do hook this up to the dynon D-120? I do not have a sinle P leading coming from the mag Are there detailed directions? Am on vacatin ad will be back the 29th. Would like to order the parts so they wil be there when I return.

Thanks

Mel from Colorado

Brantel · #6 08-20-2011, 08:05 PM

Take a pic and let us see what you have. Most likely you won't need any parts...

cfiidon · #7 08-21-2011, 11:46 AM

See the following link, page 3-4

http://www.dynonavionics.com/downloa...on%20Guide.pdf

You should not have two leads from the right mag to the Dynon for the tach.