DIY Tacho Transplant for ECU, keeping Your Original Dash

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STEVOOOish
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DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by STEVOOOish »

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Hello, here is a new 5v Tacho body on the face of my old original 12v Tacho. This was completed due to having a SR20det in a Holden Gemini. The original Gemini tacho runs from a distributor 12v pulse the SR20det only has a ECU signal of 5v hence the requirement of the transplant.

I posted this as there is not a lot of info on a simple task and i wanted to help.

I was dedicated to keep my original dash with ZERO aftermarket gauges hanging off.

I tried a pull up resistor on original set up which only worked for short time.

I purchased a $17 tacho from Ebay.. just type in Tacho and a million of these come up. some cheaper from OS.

1) Remove outside cover of tacho
20150630_193928.jpg
2) Remove the Original Tach needle and pull it apart carefully. Remove the metal shaft from original tach needle
20150630_205539.jpg
3) Remove the plastic center from the aftermarket tach and simple (carefully) cut the red needle down so you are left with the center point of the needle. this will be stuck onto the original gemini tacho with super glue so it will covert the original needle to fit the after market tacho body.
20150630_205611.jpg
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Last edited by STEVOOOish on Mon Jul 13, 2015 10:46 am, edited 2 times in total.
SR20DET TG 1984 (170rwkw grandpa car)
STEVOOOish
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by STEVOOOish »

4) Position the aftermarket tacho face on the original tacho as per image and stick it down with tape. This needs to be accurate as it will be the mounting point of the aftermarket body.
20150630_212515.jpg
5) Drill the holes with care.
20150630_213021.jpg
6) Find suitable screws to attach aftermarket body to original face. mine are from the DVD remote
20150630_220829.jpg
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SR20DET TG 1984 (170rwkw grandpa car)
STEVOOOish
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by STEVOOOish »

7) Mine was for a SR20det gemini for some reason when i connected this it did not work. i had to place a diode as per below diagram. i assume this regulated the signal
Diagram.jpg
8) please see link for working result

https://www.youtube.com/watch?v=6hIX2smkSAs

so happy with the result as i have a working Speed and Tacho. looks 100% original and only cost me $40-$50 to set the Speedo and Tacho up.

ps i did have to twist the needle slightly for the correct calibration.

This will work for ECU convertions for V8, V6 and cylinder.
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SR20DET TG 1984 (170rwkw grandpa car)
GEMWRC
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by GEMWRC »

Very well done Steve
This type of mod is exactly what i like to see :)
STEVOOOish
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by STEVOOOish »

GEMWRC wrote:Very well done Steve
This type of mod is exactly what i like to see :)
Thanks bud :)
SR20DET TG 1984 (170rwkw grandpa car)
DR_GEM
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by DR_GEM »

Great mod and thought process

Simple but critical.
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Jonno
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by Jonno »

f*#cking brilliant!

I'll sticky this somewhere so everyone can see.
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sandy
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by sandy »

this excites me haha
STEVOOOish
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by STEVOOOish »

hahmmmmm* lil chuffed i got a Sticky :)
SR20DET TG 1984 (170rwkw grandpa car)
GEMWRC
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by GEMWRC »

Y0u Deserve it Steve


f*#k yeah Woooooooooooooo
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mitchellgeci
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Re: DIY Tacho Transplant for ECU, keeping Your Original Dash

Post by mitchellgeci »

6) Find suitable screws to attach aftermarket body to original face. mine are from the DVD remote
Haha! Love it!
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