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Done? It's never done!
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Discussion Starter #1
I'm in the middle of an aftermarket tach install and I'm wondering which wire do I need to tap in order to get the reading for the tachometer. Right now I have the black wire behind the stock tachometer tapped. Is that the right one, or do I have the wrong one tapped? Might explain why my defi link tach doesn't work. Anyone know which wire it is?
 

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stop pulling me over pigs
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Good question. This is common for a lot of cars, I always wondered about this, but I never hooked up any aftermarket tachs - I'd say search the forum, or even google. Gotta be easy, all the riceboys have them. :D
 

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Done? It's never done!
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170 Posts
Discussion Starter #4
yes, so therefore it should be easy to find the info. However I tried searching around for it and nothing really seems to turn up. ::sigh:: almost had it but maybe it's the wire next to the one I tapped. Looking in the shop manual, there's apparently 2 wires that go into the tach for the signal I believe. One would be the positive and the other the negative (anyone know?).

What's the location of the diagnostic port for ignition?
 

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Done? It's never done!
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170 Posts
Discussion Starter #6
hmmm strange, I tapped the black wire going into the tachometer and I can read a signal from it on an ohm meter. When I plug it into the defi link box or even my dad's '85 Suntune tachometer, it doesn't seem to respond. It should be the same wire if it's responding on the ohm meter to the revving of the engine right?
 

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Premium Member
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NA or Turbo first of all? aight peace :chicken:
 

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Done? It's never done!
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Discussion Starter #10
it's for a turbo car
 

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Done? It's never done!
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Discussion Starter #11
ok, I tried contacting horsepower freaks from where I bought it from and they contacted Defi. Answer was that I didn't have the right wire. So then I tried tapping into one of the lines coming off the ECU that they said and it gave a signal on the ohm meter. (Light green/black wire). However when I plugged it up into the Defi link control unit II the gauge would not register, yet again. Is it supposed to work or could it be that either the Defi-link control unit or the tachometer is faulty? This would be so much more easy on the n/a with the distributor. Just hook up to negative coil.
 

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What was wrong with the wire in my above post?
 

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Done? It's never done!
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Discussion Starter #13
well I tapped that one and it had a response on the ohm meter, but nothing happened on the gauge itself.
 

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I think you may have a faulty tach or it need some strange signal, cause it worked great for mine. I'm betting it's a bad tach, because the signal most tachs use has become pretty standard.
 

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Us And Them
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I'm not sure if this is the same wire but it sounds like it to me,
WHen i was installing my alarm i needed the "tach signal" in order to use the remote start and i can tell you for sure that the one i used (that worked) was coming out of the diagnostic plug (under the hood) it's a black wire with orange (<-- i think) traces. And that's all there is too it.
 

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Buddy thought I had a NA
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2,476 Posts
i going to be putting in shift ligth but instead of useing the black wire fomr teh ignitor it;'s selkf what pin out on the ecu can i use


i can sema to fidn the negtive on it my book sucks
 
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