HELP: MGL RDAC/RPM wiring

Hi Guys

Need some input from guys with MGL avionics.

I am using the T1A9-1(Sold by MGL) sender mounted to my magneto to pickup RPM reading. This is wired directly to the RDAC X unit.

The instructions I received in the box say not to wire a resistor between the power and signal but then the online instructions say you need one?

Can someone tell me if this would cause me not to get a RPM reading at all?

Thanks AJ

Call Matt

I would call Matt and ask him. But my recollection is that MGLsupplied a resister that I installed on the RDAC between two terminals, one of which is the RPM input terminal.

More info

I went back and looked at my paperwork. Red is power. Black is ground. And white is the input signal. There is a 22k resistor between the red and white. Mgl website has "Lycoming Engine Sender Installation Guide" which is what I went by and all works well. The only additional thing I had to do that is not in the guide is add an auto parts store in line fuel filter to the manifold presure sensor pneumatic line from the cylinder head to the RDAC to act as an accumulator to dampen manifold presure pulses to get a steady reading.

Email from Matt

Hey guys

Thanks for the replies.

I emailed Matt and he said the resistor is not needed?
But I'm starting to think otherwise, I have also see the lycoming install instructions and they were different to the ones I received in the box.

I will be wiring a resistor between Red and signal and give it a go.

thanks again guys

AJ

I put resistors on mine its gives you a little protection and a little filtering