Aftermarket Tach install

[JSkwarek]

For those of you that have installed an aftermarket Tach in your car, where did you get your RPM signal? Did you go to the negative wire on one of the coils, pin 25 on the middle ECM plug or did you go with a Tach Adapter. Looking to do this install soon and looking for path of least resistance.

I hooked up my N2MB to the computer harness and it was an absolute pain in the arse to get in there to do it so would rather not go that route, again.

TIA,
Jason

 

[nxhappy]

coil wire will be best ...

 

[Mr. Freeze]

what kind of tach are you installing?

 

[JSkwarek]

I'm installing the AutoMeter CJ Tach. I didn't think you could grab the wire off the coil, NXHAPPY. Have you done this, or are you assuming it will work? All my research states the only thing that works off the coil wire are the Raptor shift lights.

It looks like there's a way to cut the wires at the fusebox under the hood that go to the coilpacks but I'm always concerned with doing something like that as I could potentially lose full power to the coils due to cutting and soldering in the AutoMeter adapter. And... if the adapter were to fail, I'd have no power.

JS

 

[Mr. Freeze]

getting the signal from the coil is the only way i've heard of it working. Found this on the net too, don't know if its of use :::http://www.americanmuscle.com/fordracing-tach-install.html

When you get it installed and working post pics. im curious to see how it looks like all it up and working.

 

[JSkwarek]

I will definitely document the install and post pictures. It looks as though I'll need the AutoMeter Tach Adapter but in my studies most people go to the fuse block under the hood and separate the two red wires that run to the driver and passenger coil banks and solder in that way. I hate to go there because I'm worried about potential failure or drop in voltage from breaking those lines and adding in length of wire.

I did some more thinking last night and have already cut into both coil banks at the BEC to run my N2MB WOT Box, so I think I can grab the signal from there, inside the vehicle at the WOT Box and make my life easier. We'll see, Tach should be here next week.

JS

 

[Mr. Freeze]

I will definitely document the install and post pictures. It looks as though I'll need the AutoMeter Tach Adapter but in my studies most people go to the fuse block under the hood and separate the two red wires that run to the driver and passenger coil banks and solder in that way. I hate to go there because I'm worried about potential failure or drop in voltage from breaking those lines and adding in length of wire.

I did some more thinking last night and have already cut into both coil banks at the BEC to run my N2MB WOT Box, so I think I can grab the signal from there, inside the vehicle at the WOT Box and make my life easier. We'll see, Tach should be here next week.

JS

awesome news! looking forward to seeing how it turns out. People hate tachs but i hate looking down and for some reason the bigger numbers help me focus on the road instead of looking down on smaller numbers. God i hate getting old

 

[ghig50]

Does anyone have any pictures of where pin 25 is and or exactly where they are tapping into the coil pack.
I have installed a lot tachs but on cars with distributors mad boxes etc.
I have looked around on the net for pics just want to be sure before I cut or tap into a wire.

 

[ghig50]

Ok If no pictures maybe just a better description or link to a thread still not able to find anything 100%

 

[LEXiiON]

I am not sure if PIN 25 is correct. It tells me MAF sensor. The coil plugs on these cars have 2 pins. One is + going to a central location on the BJB and the other is going to the PCM. Based on what I read in the diagrams, the one going to the PCM for each is the negative. The central power feed for both banks is coming from the BJB Fuse F40 (2007-09).
Here is the diagram.



Hope this helps,

LEXiiON

 

[ShiftyThePirate]

Don't the Aeroforce Gauges just plug into your OBDII port and gather all of this information? Seems a heck of a lot easier than going through wiring into a coil..

They aren't cheap but they are plug and play. Should without question gather RPM. 400$ for the dual gauge and you can add on 200$ or so for the a\f ratio sensor and the oil sensor, but they go out of stock wicked fast. Still, seems a heck of a lot easier than what you are installing, it is plug in and drive.

 

[ghig50]

Thanks that should help. I believe I just have to tap into any one of the coil wires.

 

[ghig50]

Don't the Aeroforce Gauges just plug into your OBDII port and gather all of this information? Seems a heck of a lot easier than going through wiring into a coil..View attachment 65180

They aren't cheap but they are plug and play. Should without question gather RPM. 400$ for the dual gauge and you can add on 200$ or so for the a\f ratio sensor and the oil sensor, but they go out of stock wicked fast. Still, seems a heck of a lot easier than what you are installing, it is plug in and drive.

From what I can see the torque app will do more than the aeroforce gauges. What I am installing is a aem failsafe wide band that can do data logging it also has the option of showing the rpm on the software plotting that is why I am looking into the correct way of installing the rpm signal.
Plus I will be timing this into my sct to do data logging.
I am assuming that. Many have tapped into the coil for signal just want to see exactly how.