Hi everyone. If you are like me, and you run coil on plug ignition or coilpacks, you probably have connected the tacho wire and noticed that the tacho doesnt function. Mine would do the odd jump and show different data if you turned the lights on or went into reverse, etc. It never actually worked in the 3 years Ive had a 20v ae71 on the road.

I decided yesterday enough was enough so I found the info for the GZE tacho mod into ae86. I then did a few experiments with my tacho to get it working as it should.

The ae71 has a different Tacho circuit board to any other corolla. It has a variable resistor from standard to adjust the tacho readout which is something that nobody has noticed on other corollas from what I can tell. Its quite cool really.

The process for adapting your tacho so it will function correctly is quite simple and outlined in the below before and after photos.

You will need one 15kohm resistor and and capacitor. If you want a greater range of adjustment you can go to a variable resistor with a greater range of adjustment.

Before:
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After:
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