no signal for tacho

[CSL]

yea you dont need a converter.
like mentioned you can use one of the cluster wires, the cluster is labeled so you can trace which wire o what. the plastic slip for the cluster plug just pops out with a couple of screw drivers. or use the brown wire coming out of the ignitino module, however that could be the same wire listed above.

 

[ashzv6]

under the steering wheel, theres a bunch of wires that go to the dash.
its the brown wire with red stripe,
so many ppl have said this wire in the engine bay doesnt work.
my tacho works fine off the wire near the steering wheel.

 

[coolvxss]

Yeah same. Both wires work fine with me.

 

[andrewownsavp]

About Time

Ok everyone i had all the same problems with the tacho bullsh*t ive worked it out. for all the people with in dash tacho have no problems with it. This is the trick you have to do it in your dash if you havent got a indash tacho. This is whats got to happen behind the instruments on the dash its got numbers 4, 5, 6 you have to get the wires from the tacho into 4,5,6 this is the trick the workshop manual doesnt say.

1. hook the earth from the tacho into 4 it will be black wire behind the instrument dash.
2. for tacho ignition from the tacho go the red wire to 5, it will have a pink and black wire there.
3.The green wire goes to 6 which is the tach signal wire it will be brown and red.

many weeks it got me beat and no one new and this is how i figured out mine i tried 3 tachos to the tach terminal in the engine bay and they didnt work and i spoke to 5 professionals that didnt know and this is how i got mine to work. anyway good luck hope this solves everyones probelms

 

[WhiteLightning]

what brands or breeds of tacho work on the so-called 5 volt square wave signal that the ecu provides...

 

[ptitkev]

tacho signal for vn v6

got my signal off a brown wire hanging out of the wire bundle going to the dashboard...found near the passenger side shocker... its got a white sorta clip or plug...worked fine...

 

[nugatory]

what brands or breeds of tacho work on the so-called 5 volt square wave signal that the ecu provides...

the ones the car came out with!

 

[azzfox]

5 volt square wave signal?^^ ever put a multimeter on the signal wire? the voltage increases with rpm. also know of a bit of a trick.. set a multimeter to 200mV or 2000mV DC (cant remember which works best) and put it on the signal wire and the numbers it reads is pretty much spot on rpm going by stock tacho.

 

[nugatory]

5 volt square wave signal?^^ ever put a multimeter on the signal wire? the voltage increases with rpm. also know of a bit of a trick.. set a multimeter to 200mV or 2000mV DC (cant remember which works best) and put it on the signal wire and the numbers it reads is pretty much spot on rpm going by stock tacho.

That actually sounds pretty neat... a multi meter to tacho conversion, with blue backlights too... I've thought about this conversion way too often with other units e.g. subwoofer power drawage etc.

Are we talking about this wire from instrument connector #2 pin 3 - "Brown/Red - Circuit 121 - Tacho signal - Voltage V6, engine running, approx 1 volt at idle, voltage increases as speed increases.V8, engine running, approx 12 volts at idle, voltage decreases as speed increases."

Hence there's no square wave signal, the whole tacho is controlled by voltage which explains Azzfox's theory on how the multimeter can show spot on revs, because if it's 12v when the car is doing 5,800 (close enough to 6,000) revs, then put through a 200mv calculation (which should half the figure) will then show the revs. If it's roughly 1volt around idle, it's most likely around 1.6v to give 800-1000 rpm.

This would be pretty cool alongside a digital Shift Light - just hook an LED up to the light and when it's bright... CHANGE GEAR!

This would only work in a V6 though. In a V8 the tacho starts at 12v and works it's way downward, which would be a pretty funny tacho and you'd have to change gear when the LED went out instead.

I think he's gotten lost looking in the wiring into the PCM / ECM as there's a 5v signal that pulses electronic ignition spark info from the ecu to and from the pcm (whatever that means!).