tacho output to 1980's cressida digital dash

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joooeone
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tacho output to 1980's cressida digital dash

Post by joooeone »

hello every on im trying to make my digital dash to work with the ms3x ive all ready got fuel temp and other stuff working on the digital dash the only thing left is the rpms signal ive try the tacho output from the expansion pack and try the iac1a signal from the ms3x and no response it docent show me no rpm signal is there a special setting that i need to do or do i need to buy a msd tach converter box to make it work?

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i heard from another forum that the signal is digital and you need to convert it to a different signal like a old signal i don't now if im explaining it well

like these one http://www.jegs.com/i/MSD/121/8920/1000 ... AhBt8P8HAQ
prof315
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Re: tacho output to 1980's cressida digital dash

Post by prof315 »

Do you know how the tach was originally triggered?
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joooeone
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Re: tacho output to 1980's cressida digital dash

Post by joooeone »

It says on the wiring diagram by the ingnition coil
elaw
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Re: tacho output to 1980's cressida digital dash

Post by elaw »

You might need something like the third circuit here: http://www.msextra.com/doc/ms2extra/MS2 ... m#tachoout (the one titled "Options for High Voltage tacho's")
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elutionsdesign
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Re: tacho output to 1980's cressida digital dash

Post by elutionsdesign »

On those 80's dash tachs driven by the negative coil you can often trace the input wire into the dash to a large resistor in series. It was put there to dissipate some of the power (voltage) spike, if you find that arrangement on your dash you can jumper that resistor and use the tacho out successfully. If not the link Eric provided has a couple of options that will work as well.
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joooeone
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Re: tacho output to 1980's cressida digital dash

Post by joooeone »

im a newb when it comes to customize the ms3x from the inside.....will a msd tach converter work?
knightrous
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Re: tacho output to 1980's cressida digital dash

Post by knightrous »

You need a high voltage trigger for the tacho, you can build one for a few $'s using a relay.

http://www.toymods.org.au/forums/showth ... ost1017046

I set one up on my DIYPNP to run the stock tacho on my Toyota MR2 AW11.

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joooeone
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Re: tacho output to 1980's cressida digital dash

Post by joooeone »

i like the tacho booster the external one it looks easy to fabricate i will buy whats needed tomorrow and try it and will post the results thank you for the help
suberimakuri
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Re: tacho output to 1980's cressida digital dash

Post by suberimakuri »

I did Mode 2 in this link with MS3X tacho out.
http://www.adaptronic.com.au/forum/inde ... 2034;image
In AE70 corolla, old style ignition negative dash.
joooeone
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Re: tacho output to 1980's cressida digital dash

Post by joooeone »

it work im so happy!!!!!! amazing what some lights in the dash can make you feel lol
elturbonitroso
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Re: tacho output to 1980's cressida digital dash

Post by elturbonitroso »

Ok guys I'm having the same problem on my car can I share the tach output on the ms3x to activated the shift light on my car and the transistor of the relay method.thanks
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Re: tacho output to 1980's cressida digital dash

Post by suberimakuri »

That won't work sharing shift light and tacho.
MS3X has so many outputs why not use a different one.
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Re: tacho output to 1980's cressida digital dash

Post by jsmcortina »

Sharing an output is a bit like sharing one pipe for gas and water. It isn't going to work.

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elaw
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Re: tacho output to 1980's cressida digital dash

Post by elaw »

Unless he meant that the shift light was driven by an existing circuit that required a tach signal.

But without knowing anything about the car, who knows? :?
Eric Law
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elturbonitroso
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Re: tacho output to 1980's cressida digital dash

Post by elturbonitroso »

Yes the shift light has its one circuit just need a 0-12v tach signal.
elturbonitroso
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Re: tacho output to 1980's cressida digital dash

Post by elturbonitroso »

Yes or no guys.thanks
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Re: tacho output to 1980's cressida digital dash

Post by suberimakuri »

two functions, use two outputs, one output for each function.
racingmini_mtl
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Re: tacho output to 1980's cressida digital dash

Post by racingmini_mtl »

It might work but that depends on the tach and the shift light circuits and the circuit you use on the MS. The only way to know is to try it.

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elturbonitroso
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Re: tacho output to 1980's cressida digital dash

Post by elturbonitroso »

ok im going to built the hi voltage tach output and I want to know if I can replace the 2n5551 transistor with a tip120 since that's what I have with me right now and the electronics store its an hour away.thanks
elturbonitroso
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Re: tacho output to 1980's cressida digital dash

Post by elturbonitroso »

Karl_Skewes wrote:I did Mode 2 in this link with MS3X tacho out.
http://www.adaptronic.com.au/forum/inde ... 2034;image
In AE70 corolla, old style ignition negative dash.
im going to try mode 2 on this link using the ms3x output to feed the relay and hoping that my that work because im running out of ideas.
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