Defi Tach Wiring | SR20

[conrad_s13.5]

Ive done alot of searching to pretty much reach a dead end on every discussed thread.

RPM signal wire does not work. I know people have successfully got these running with SR20's time and time again. But no way is everyone buying tach adapters and tearing up their coilpack wiring.

Ive heard of tapping into #1 coilpack ground, or into the CAS wiring,. but im not trying to butcher a bunch of wires for trial and error, so kind of hoping someone can chime in and help a ninja out!

[G5SR20240]

It's as simple as finding the source from the ecu, find a schematic and make sure that the defi gauge is wired up correctly, should work unless gauge is bad

[Geno750]

It's as simple as finding the source from the ecu, find a schematic and make sure that the defi gauge is wired up correctly, should work unless gauge is bad

Not true.

Here is how I had to wire up my Defi Tach for it to work.

http://airepoweraviation.com/carprogress/defidiagram.jpg

[LayNLow]

What exactly does the resistor and 12v source do for the tach signal that lets the defi gauge read it?

[brndck]

Yeah I don't see why you would be running a power wire into a signal wire.

[Geno750]

The simple answer is, when I bought Defi's, it was what I had to do to get it to work.

First start with the Haltech P1000 - YouTube (http://www.youtube.com/watch?v=uvQyVyX2ZTQ)

[conrad_s13.5]

I wish it was as easy as finding they signal wire,...cuz that was the first thing i did.

Ive been seeing that everyone that got these to work seamlessly, still had the oem cluster and tach AND Defi tach, and only then it would work. People trying to replace broken tachs, or all after market gauges ran into my same problems.

So maybe the same sort of resistor is built into the cluster, to give it the power it needs to read the signal correctly??

ninjaedit: dude,.. love the cluster / dash set up Geno!

[LayNLow]

The simple answer is, when I bought Defi's, it was what I had to do to get it to work.

First start with the Haltech P1000 - YouTube (http://www.youtube.com/watch?v=uvQyVyX2ZTQ)

How did you come to the conclusion that the resistor and 12V would make it work? I ask not because im trying to make it seem like you are stupid, I ask because I am working on making my own cluster setup with 5 DEFI's. One of which is a tach. I just want to know how you found out that would work.

[fliprayzin240sx]

Is the tach atleast working but not registering it accurately or nothing at all?

[Geno750]

How did you come to the conclusion that the resistor and 12V would make it work? I ask not because im trying to make it seem like you are stupid, I ask because I am working on making my own cluster setup with 5 DEFI's. One of which is a tach. I just want to know how you found out that would work.

I couldn't tell you the specific technical answer. It was just what a friend of mine who is much smarter than I am when it comes to electrical systems told me to do when I encountered the OP's problem.

[LayNLow]

I couldn't tell you the specific technical answer. It was just what a friend of mine who is much smarter than I am when it comes to electrical systems told me to do when I encountered the OP's problem.

Ahh, gotcha. Which of the two tach wires did you use on the defi?

[conrad_s13.5]

Is the tach atleast working but not registering it accurately or nothing at all?
Yes sir. Came out of a car working just fine. Lights up and displays the start up sequence. Wouldnt read a damn thing off the signal wire. Played with coilpack wires and it would read inaccurately.

Im going to try this method this week, and post my results

Appreciate the help guys!