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-   -   Haltech How To Get FD3S Tach & Speedo Working (https://www.rx7club.com/haltech-forum-62/how-get-fd3s-tach-speedo-working-760375/)

adunlap 05-30-08 06:04 PM

How To Get FD3S Tach & Speedo Working
 
There seems to be a lot of dissinformation on how to do this so here's how I got mine to work using the Haltech E8.
First off, the tach is NOT run off the igniter or the coil or whatever. That is only on the 1st and 2nd gen.
You will need to remove the instrument cluster from the dash or pull it out enough to get at the wiring connectors. Two screws hold it in at the bottom and then it pulls straight out. You will have to remove the plastic pieces around the bottom and steering column.
Once it is out you will see three major harness connectors. One left, one center, and one right.
On the left connector will be a black with blue striped wire which will be bigger than the rest. You will need to strip some of the casing back and solder a ground to this wire. Do not cut it. By doing this you will only be grounding the instrument cluster and you will lose the ground to your fuel tank sender.
After this you may notice some of the lights on the dash glow a bit brighter. The low coolant/low oil level alarm will probably go off too. If you are not going to use these cut the Brown/White striped wire and the Light Blue wire from the center connector. The alarm should go off.
Next, find the Yellow/Blue striped wire on the stock ECM harness (passenger side kickpanel) and connect this to the hatech's PWM1 output. This will be a violett/white wire on the E8.
Use these settings:
Output - Normal
Pullups - 12v
% duty - 10%
Pulses per cycle - 8

and Vola! Enjoy!

adunlap 05-30-08 06:10 PM

Fyi, all the threads on this forum say to use the blue with yellow striped wire. This won't work :squintfin

Use the yellow, blue striped wire.

crispeed 05-30-08 07:24 PM

The yellow with blue stripe always work for me. You just got to know where to tap into that wire! :lol:
Also the negative side of the coil also works.
All my cars I do don't even use the factory igniter and I get perfect signal through the Y/L wire from the tach output on the MSD.
You don't need to hack up your instrument cluster to do that. Where do you think the RPM signal comes from for the tach in the cluster?
Also the add coolant signal is right next to the motor by the PS pump. All you have to do is extend the wire to the coolant level sensor or if you're not using one just ground the wire to deactivate the warning buzzer/light.
Water temp signal, low/medium speeds for the fans and ground for the dash/cluster etc. just to name a few can all be activated through the white and blue plug/connector where the factory harness use to plug into next to the ecu.

adunlap 05-30-08 08:49 PM

Yes you could also use the ignition 1 out to drive the tach but I worried about what it would do when the timing changes suddenly. PWM 1 gives a steady tach signal.
You DO have to ground that wire behind the gauge cluster otherwise the system will not get a good ground and wierd things will happen (like the tach and speedo moving together!). The tach will not work until this is done. There are actually three grounds to the gauge cluster, but the other two were fine.
For some reason I only had to cut the wires to the oil and coolant level senders to make the alarm turn off :scratch: I don't quite understand this, but it worked for me.

crispeed 05-31-08 01:05 AM


Originally Posted by adunlap (Post 8241590)
Yes you could also use the ignition 1 out to drive the tach but I worried about what it would do when the timing changes suddenly. PWM 1 gives a steady tach signal.
You DO have to ground that wire behind the gauge cluster otherwise the system will not get a good ground and wierd things will happen (like the tach and speedo moving together!). The tach will not work until this is done. There are actually three grounds to the gauge cluster, but the other two were fine.
For some reason I only had to cut the wires to the oil and coolant level senders to make the alarm turn off :scratch: I don't quite understand this, but it worked for me.

All the grounds go to one of the plugs close to the ecu. From there it goes to the top of the rotor housing. The reason the factory cluster grounds directly to the block is so as not to induce a ground offset for the factory gauges to read accurately since all the sensors are located on the motor. Sensors and gauges on the same ground. If you did it the way I said everything functions like factory and there's no need to cut or splice anything.
The factory enginered the oil and coolant level sensors for a reason.

adunlap 05-31-08 04:59 PM

Ok, well to recap:
If you have retained some of your factory harness then you may only need to give it a tach signal. If you still have no tach or speedo, ground the wire behind the cluster.
My car no longer has the factory engine harness so this was how I solved my problem. I'm sure others are in the same boat.
Good luck...

crispeed 06-01-08 02:12 AM


Originally Posted by adunlap (Post 8243758)
Ok, well to recap:
If you have retained some of your factory harness then you may only need to give it a tach signal. If you still have no tach or speedo, ground the wire behind the cluster.
My car no longer has the factory engine harness so this was how I solved my problem. I'm sure others are in the same boat.
Good luck...


You still don't need the motor harness. Everything you need is located right at the factory ECU location. :)
Hint: White and blue connector plugs.

theakisrx8 03-29-12 11:34 AM

Hi...
I could ue sme help here please...
I'm Greek so my english isn't that good to understnd everyhting in here.... :(

I'd like to ask you which wire behind the cluster is the signal for the speedometer, so i could use it to connect it to AVI3 input of my P1000 ECU...
Any groundings also that would be necessary...?

I really don't know why my electrician wants to do that...:scratch:

Please advise....

dznutzuk 04-04-12 05:58 AM

I hook up the stock tach straight from the ls2 ignitors and it works just fine(this being for the FD). Aki, καλυτερα ειναι να βρεις το πρασινο/κοκκινο(1Μ) καλωδιο απο την εργοστασιακη πλεξουδα μεσ'την καμπινα. Εκει βρισκεται το καταλληλο σημα για road speed εκτος αν δεν ειναι για 7αρι και ειναι για 8(τοτε δεν ισχυει)? Αν χρειαζεσαι κατι παρε τηλ 6972279479 Σπυρος

samad 07-07-14 03:02 AM

Reviving this thread for a similar problem i'm having with my FD. Its a 99 JDM auto transmission.

The rpm does not work at all, every now and then it gives me a very slight movement. Also there is a whining noise that comes from the passenger side when I press the accelerator about 30%. It goes away as the speed increases, so this is happening basically at lower rpm's. The noise also goes away when I let go of the accelerator. Dont know if the noise is related to the rpm issue.

help would be appreciated.

thatkid2007 08-06-14 08:56 PM

I am having the same problem, please help!

samad 08-07-14 03:46 AM

So I had all of the points in the rpm circuit resoldered and the rpm works now. Only issue is I think I screwed up the position of the needle, so it idles at 2000rpm now. Im going to try and reposition it later. Its such a pain in the ass removing everything.

b3delta 09-14-17 04:37 PM

Revival. My car is a 94 PEP. The tach only work if the car has been in the sun all day and it's really hot. The cluster has been replaced and the same thing happens. Where else could the issue be?
Any specific grounds to check, other connections?
LAst time I had the cluster out (couple months ago) I cleaned all the contacts and the 3 screws for the tach, and nothing.
Being that it works when its hot out seems like a weak connection and the expanding metal makes a contact, but where?

Thanks


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