Vans tachometer transducer

I just received a Vans tachometer transducer. It came with no wiring instructions. It has three wires: red, black and white. I would guess that red is for 12 VDC, black is ground and white is the tach signal out wire. Before I hook it up, does any one else have the Vans tach transducer that has already hooked it up and can verify the wiring pinouts?

All three wires go to the back of the tach. Red goes to "I" terminal and +12v bus.
Black goes to "G" terminal and ground. White goes to "S" terminal.

Mel said:

All three wires go to the back of the tach. Red goes to "I" terminal and +12v bus.
Black goes to "G" terminal and ground. White goes to "S" terminal.

Click to expand...

Thanks Mel!

I guess I should have added I dont have a separate tach. I am hooking the transducer up to a Dynon EMS-D10A. I will run the red to 12v, black to ground and the white to the dynon tach input.

Using a cable is the way it is done. I think Vans sells a short tach cable for that purpose.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

Go back to Vans

and buy their 12" tach extension cable. Discard the short 2" extension (looks like a long hex nut) and cable that came with the original transducer. I built a bracket to mount the transducer on a nearby engine mount tube above the right mag. While at Vans, buy another rubber crankcase vent hose and possibly another alum tube because you'll need to re-route the vent line around that oil filter, too.

ECI -9A,
Steve

rvator51 said:

Thanks Mel!

I guess I should have added I dont have a separate tach. I am hooking the transducer up to a Dynon EMS-D10A. I will run the red to 12v, black to ground and the white to the dynon tach input.

Click to expand...

If using Vans tach. Gen. Be sure to set the Pulse/Rev on the EMS-10A to #4 so the EMS RPM matches the actual engine RPM. Press on. Dick Bentley

Wiring diagram

Wiring diagram and instructions for Vans gauges can be found here:

http://vansaircraft.com/pdf/Gauge_Install.pdf

What's the difference between the two transducers Van's sells? one's "with vacuum pump" and the other is "without vac pump"... I guess I'd need the extension as well since I have the same 90 deg adapter..

Which one do I need/want?

I don't have a vacuum pump, but I have a B & C 20 amp alternator on the vacuum pump pad.

Do I need the Vans tachometer transducer with the extension....or will the transducer without the extension fit.

Captain Avgas said:

I don't have a vacuum pump, but I have a B & C 20 amp alternator on the vacuum pump pad.

Do I need the Vans tachometer transducer with the extension....or will the transducer without the extension fit.

Click to expand...

I've got a B&C 8 amp alternator on the vacuum pump pad, and Van's tach transducer wouldn't fit. I had to purchase the extension. I assume the 20 amp alternator is no smaller than the 8 amp one, so you almost certainly need the extension.

Radomir said:

What's the difference between the two transducers Van's sells? one's "with vacuum pump" and the other is "without vac pump"... I guess I'd need the extension as well since I have the same 90 deg adapter..

Which one do I need/want?

Click to expand...

The one that says "with vacuum pump" has a 12 inch extension cable on it so you can put the transducer on the firewall or bracket it to the engine mount tube. I have a B&C 20 amp on the vacuum pad, and I definitely needed the extension cable.

FYI you can get one made locally at any shop that does speedometer cables if you need a different length.

PJ Seipel
RV-10 #40032

I have a B&C 20 amp alternator on my vacuum pad so the standard Vans tachometer transducer will not fit. I have therefore opted for the Vans transducer with the 12" extension cable. I have attached a photo of the installation. You can see the cable highlighted with a red arrow.

In checking throught the archives I see that a number of builders who needed the extension cable have mounted the transducer on the engine mount.

In my photo you can see that I have temporarily taped my transducer to the engine mount to visualize the layout.

The problem with fixing the transducer on the engine mount is that the extension cable must change direction through almost 180 degrees. And I have a gut feeling that the drive core inside will not like that change in direction over an extended period of time.

I would therefore like to ask anyone who has the 12" extension and has fixed the transducer to the engine mount whether they have had success with this configuration for a reasonable period of time (+300 hours).

Alternatively I would also welcome comments from builders who have had operational success by fixing the transducer to the firewall (or even taken it right through the firewall).

Any photos of installations would of course be more than welcome.

Bob, you can make up a standoff bracket to put it on the firewall.

Bend up a piece of alum to an "L" , make one leg long enough to clear the diameter of the transducer when mounted to the bracket. Other leg rivets to FW. Real simple piece, use TLAR engineering.

The cable will then make a 90* bend only.

no pics

"Bob",
I used Vans belt drive alternator so I ran my 12" tach drive cable to the top right engine mount tube. This routing also permits easy access to the oil filter when using the ECI 90 degree adapter. I've got 152.0 hours on the plane so far without problems. My tach cable is bent somewhere between 90 and 180 degrees, though.
I know a -7 builder who ran the tach cable through the firewall but he's since changed it when he went "glass".

Steve