# Aftermarket tach install on ka24e hardbody



## bascom01 (Feb 22, 2012)

Hey I'm new here and I'm having a problem installing an aftermarket tach.... My problem is which wire @ the coil do I splice into.... What are my options???? I heard I can also do it at my ecu and also at the tach plug behind my gauges..... Problem is I don't wanna pull my cluster or chance somethin too close to my ecu unless I gotta. Lemme know what I gotta do at the coil or verify other options. Btw info on my truck.... 93' 2wd manual w/out oem tach gauge. If u wanna get hold of me u can email me @ [email protected] thanx 

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## TheRepairMan (Jun 30, 2009)

I don't have the wire colors, but you want to hook your tach signal wire to the wire on the (-) side post of the coil that does not have power on it with the key on.

If you aren't sure you can take a test light and check for power on either wire going to the primary side of the ign coil. The only thing is... you MUST take at least one of those wires loose from the coil first before testing for power on them, otherwise your light will light on both sides of the coil circuit.

~R


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## Asleep (Jan 19, 2003)

im fairly positive that plug going into the coil is marked. if its not, nissan is pretty good about using similar wire colors across the board for each car.


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## bascom01 (Feb 22, 2012)

Well Thing is my coil isn't an old school style like the old chevys and fords... My coil has 2 different plugs with 6 different wires comin outta it. But I know what Ur sayin cause my tach came with a wiring diagram for the older coils w/ the neg and Pos sides

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## bascom01 (Feb 22, 2012)

Oh and my plug isn't marked that I can tell

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## Asleep (Jan 19, 2003)

rewriting what i wrote before... is there a blue wire on the plug that goes to the coil? according to autometers website, the blue wire is nissans signal wire for the tach.


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## TheRepairMan (Jun 30, 2009)

Asleep said:


> rewriting what i wrote before... is there a blue wire on the plug that goes to the coil? according to autometers website, the blue wire is nissans signal wire for the tach.


That's good info. It's too dark outside for me to see mine, so I fell back on what I knew use to be. (old school)

-R


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## bascom01 (Feb 22, 2012)

Lol I actually found the right wire this morning by randomly splicing. It is the blue wire. Thanx forbthe help though guys, preciate it 

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## Asleep (Jan 19, 2003)

good to hear you got it!


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## lostsole691 (Oct 23, 2020)

I have a 1991 d21 I installed a digital tack using the blue wire from the coil and when you start the truck the tack starts reading a very hi RPM its all over the place so I don't understand what wire is the right one to tape into?


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## rogoman (Dec 16, 2004)

On your D21 there should be a tach wire connector that's unused. The connector has two wires, one should be a blue wire. If you find it, splice your tach signal wire to that blue wire. Hopefully that should do it.


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## lostsole691 (Oct 23, 2020)

I looked under the dash for it did not see it? I went to the blue wire at the coil and taped it there.


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## lostsole691 (Oct 23, 2020)

rogoman said:


> On your D21 there should be a tach wire connector that's unused. The connector has two wires, one should be a blue wire. If you find it, splice your tach signal wire to that blue wire. Hopefully that should do it.





lostsole691 said:


> I looked under the dash for it did not see it? I went to the blue wire at the coil and taped it there.


here are the two blue wires I found next to the coil neither one worked?


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## lostsole691 (Oct 23, 2020)

bascom01 said:


> Lol I actually found the right wire this morning by randomly splicing. It is the blue wire. Thanx forbthe help though guys, preciate it
> 
> Sent from my ADR6400L using AutoGuide.com App


was it one of these?


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## lostsole691 (Oct 23, 2020)

I tried both nothing worked?


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## lostsole691 (Oct 23, 2020)

rogoman said:


> On your D21 there should be a tach wire connector that's unused. The connector has two wires, one should be a blue wire. If you find it, splice your tach signal wire to that blue wire. Hopefully that should do it.


where is the tack wire located? I cant find it on my 1991 d21?


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## lostsole691 (Oct 23, 2020)

I have tried the two blue wires near the coil both did the same thing..


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## lostsole691 (Oct 23, 2020)

Asleep said:


> rewriting what i wrote before... is there a blue wire on the plug that goes to the coil? according to autometers website, the blue wire is nissans signal wire for the tach.


I used that blue wire it will not work is it becose I'm using a digital tack?


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## smj999smj (Jan 1, 2006)

I installed an Autometer tach on my 97 Hardbody many moons ago and I ran the wire to the ECM, which was what the tach instructions said to do. It was 15-years ago, so don't ask me about specifics because they left my mind a long time ago!


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## lostsole691 (Oct 23, 2020)

smj999smj said:


> I installed an Autometer tach on my 97 Hardbody many moons ago and I ran the wire to the ECM, which was what the tach instructions said to do. It was 15-years ago, so don't ask me about specifics because they left my mind a long time ago!


Ok thanks I think my tack is not right for this truck I ordered another one that says for fuel injected engines only. I have tried two new tacks both the same both did the same thing.


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