tach wont respond

[NightKids2]

I have an RB25 in an 89 hatch, LS Auto speedo and tach. I just pluged everything into the back and started the car and I get nothing. I took the yellow/blue from pin 7 and put it to the yellow/red from the back of the tach and still nothing. I guess even if I did get it to work, my cluster wont light up when the lights are one so I cant see at night anyway. Im desperate, how can I fix this?

[240+civic=pimp]

You cant , buy an autometer tach and a tach adapter 75$

[NightKids2]

...Im sure there is another way.

[Wulfgang]

You can take that $75 and buy a multimeter with frequency counter and duty cycle and use it to calibrate your stock S13 tach to read the 6 cylinder pulse.

Search forum for details.

[240HKS]

Are you sure the LS automotive tach is designed for a six cylinder signal? A good friend of mine also put a RB25 in an 89' coupe the original tach did not work so he retro fitted a tach from a six cylinder maxima and it worked fine. Try calling LS automotive for advice.

[NightKids2]

Im not saying my tach isnt reading correctly, Im saying its not reading PERIOD. I mean it says 0 RPMs no matter what. Ive tried it with a stock cluster and with the calibrated tach, same thing.

[240+civic=pimp]

Like i said buy a tach and a tach adapter. Or buy the tach adapter and from there run it to your gauge cluster. The gauge cluster now will not work because it is a destibuterless ingnition and the gauge cluster is for a distributer

[NightKids2]

Just to clarify, your telling me that none of my gauges are going to work, not even the speedo?

And your also saying, that if I were to go out and buy and Autometer tach, it should work fine?

[240+civic=pimp]

No your speedo should work fine

The tach will not work because it is a distributorless system.

You need to use a tach adapter before you hook in any tach

[Ramius83]

Ummm, under my past research, if using the STOCK gauge cluster tach, you will NOT need a tach adapter. The ECU is generating the RPM signal and relaying that directly to the gauge cluster. If you have, and even if you haven't, had your tach modified by LS Auto, it will still move/read RPMs, accurately or not.

The main problem I see hear is your tach is not getting the signal from the ECU. Re-check your tach install. You may want to hook up a multimeter and test the tach wire. Hook up one wire on your multimeter to the tach wire at the ECU and hook up the other wire to the tach wire on the back of the cluster. Switch your multimeter to current and see if it reads or not. If it does read/beep, then the wire is not cut/interrupted, and the problem may relay in the tach or tach install. If it does not read, then you need to re-check your wiring.....

[NISMO_RB25]

You guys are missing his question on this.The LS auto tach is a 6cyl tach (I have one and it works great) The 4 cyl tach that is in the car won't read correctly (but it will still move)

The problem is that he isn't getting a signal to his cluster. Unfortunately since I didn't have this problem I don't have an answer for him.

My suggestion is that you find the wire on the cluster itself and use a voltage tester to see if you are getting a signal. If you aren't back track the wire.

[NightKids2]

Im sure the wiring is right, but I have not checked it with a multi meter and Ill be sure to do that tomorrow. I also bought the cluster from a forum member, so I didnt put the new tach in the cluster and havent taken it apart to see if it was done correctly.

[y3llows14]

Is it properly grounded? Check your wiring again. Was your gauge working before? Might be an ECU problem as well---the output for rpm signal might be burnt? AccelJunky had the same problem with his ECU.

[NightKids2]

Think I heard something about grounding, black wire from the ECU? Im not sure if thats correct, or if Ive done it.

[Imissmyturbo]

When I wired up my cluster the first time I didn't wire the tach up right and got ing power to my ECU through the tach signal wire. It burn't the tach output from my ecu and my tach didn't work. I figured out if you take the wire going from the tach to the ecu and touch it to ground the tach will jump. You need to have the key on to do this. I had to replace the ecu to get the tach to work.

[frosted flakes]

240 civic pimp you dont know what you are talking about.

the tach will work. just hook up the wire from ecu tach output to the gauge cluster plugin for the tach. (i believe the yellow/red wire).

it will read 1.5x higher in the stock tach gauge cluster but open the gauge cluster up and there is a variable resistor. turn that one way or the other to get it to read right.

i have owned both s13s and s14s with rb20det and got the tach working in both cars ACCURATLEY by this method.

its not hard at all.

[240+civic=pimp]

That sound like quite a bit of work to get a ****ty stock tach to work, but to each their own.

[NightKids2]

Tried putting the yellow/red from the back of the tach to the metal bar under the dash. No jump, key in ignition and car running.

[frosted flakes]

no there is a gauge cluster plug u should splice by the passenger side glove box (underneath it). its a brown plug. just get the other end of that so u can get your tach and water temp to readup on your gauge cluster. its that easy. 2 wires to splice from your ecu to the gauge cluster plug. its a no-brainer.

use the search engine. alot of people have done it. it doesnt take an electrical engineer to figure that out.

[Slo_240sx]

He already said he had it wired up.

[NightKids2]

The other end of the white plug?

Everyone I ask keeps telling me to do something different...

To clarify, the way it is right now is the yellow/red from the back of the tack is going directly to the yellow/blue from pin 7 of the ECU.

[Bluefire]

240 civic needs to just go away...

anyways... Make sure the tach is secured with all three screws. I would trace all the wiring to the gauge cluster plug. Make sure you have continuity. Also make sure that the tach is grounded.

-Bluefire

[goofynick6]

I tried the hard way with the frequency counter like Wulfgang suggested a while back, but couldn't get it to work.

So, I used an APexi multichecker which shows rpm output, and just tuned my tach to that using the blue screw on the back of the tach. Just find something you can plug in that is a known, working tach (electrical or whatever) and match their readings..mine is within about 50rpms..I like it.

nick

[frosted flakes]

yeah its nice to have ALL the gauge cluster working. nice and stock looking instead of all the gay ricey tachs.

[NightKids2]

For the final time... my gauges are not reading OFF they are not reading at ALL. As far as I can tell, all of them but the small red lights for seat belt and battery and parking brake etc. do absolutely nothing. Can you go into detail about that other end of the white plug thing frosted flakes caues thats one I havent heard yet.

[Valley]

did you wire the correct yellow/lavender wire from the rb plug you pulled it from? write up says there's 2 of that color in the same plug.

as i have still to do this swap, sorry if i've assumed the wrong thing in my answer... but i guess i can't be to far off from the previous responses...

[Slo_240sx]

Night lol.... Everyone his tach IS NOT WORKING AT ALL!

Try using a good known gauge cluster. Has your tach worked at all before? You might have shorted it out. Try a new gauge cluster check your wiring first from the tach to the plug and then try a new ecu. 1 of 3 things.

1) Wiring. I dunno what color the wires are lemme check.... But its tach output of the ecu to the tach input on the cluster.

2) Your cluster is bad

3) Your ecu tach output is bad.

[Slo_240sx]

Ok take pin 7 of the ecu which is tach output and run it to the tach input of the cluster. Take that wire and put it to the brown plug under the dash that is Yellow/Red wire... I had to look it up but thats the input wire for the tach. if that does't work then test for continuity between the gaugecluster and the plug - if its open then there is a short or open behind the dash, If its good then check for continuity from the ecu to the wire you are putting to the brown plug. If you have continuity there then your tach or ecu is bad. Also 1 more thing, if your gauge cluster doesn't have the power and ground to run the lights, tach, speedo etc then its not going to work either. Shoot up a wiring diagram of the gauge cluster and test every power and ground. If non of that works then drive to Michigan and I'll fix it for you for free

[NightKids2]

Thanks bro, Ill be sure to try all of that when I get time next week. And if all else fails I think my brother has a g/f in Michigan somewhere, maybe I can trick him into bringing it up lol.

[JonPowell]

Get a multimeter that can read AC.

Read pin 7 from the ECU, see what you get off it should be 0.6-1.0 v at idle(depending on engine idle speed of course) and go up as you rev the car.

Try this and get back to me.