How does this shift light/tacho work?

**deviant** · 15-11-2007, 11:29 AM

My 4AGZE powered AW11 is running an EMS ECU, coil pack and using the dizzy for a crank angle sensor.

The standard tacho doesnt talk to the ECU.

The shift light/tacho pictured above is pretty cheap but looks like it will do what I want it to.

Can anyone tell me how they are wired in? I am struggling to find anything online and a call to the various distributors just reveals a "I dunno ay mate"

Does anyone have experience with them?

**lojik** · 15-11-2007, 01:12 PM

I don't know about that one specifically.

But tacho's are either triggered off the coil, or from a 5/12V square wave (normally provided by the ECU).

There are circuits floating around that convert both ways, so either way you will be able to get it working.

Actually, I just re-read your post, are you buying this because you can't get the stock tach working?
If so, one of the previously mentioned circuits will likely sort you out.

**deviant** · 15-11-2007, 01:51 PM

It would be nice to have the stock tacho working..

But to be honest I'm a real numpty when it comes to vehicle electrics so i thought this would be a quicker/easier way of doing it and seeing as I want a shift light anyway and I'm not overly worried about looks....yeah you get the idea!

So by the sounds of things I should be able to find a wire going to the ECU that just needs the stock tacho splicing in to it...

**lojik** · 15-11-2007, 02:11 PM

See the following thread for info about tacho tech:
http://www.toymods.net/forums/showth...highlight=tach

Heres a thread that tells you exactly how to build a working converter:
http://www.toymods.net/forums/showthread.php?t=22574

Its a little more complex than just splicing the wires, but by no means is it difficult to do and it will work if your stock tach is expecting input from a coil.

**deviant** · 15-11-2007, 02:28 PM

Thanks a heap for that lojik!!

I need to have a good long read of that..

**lojik** · 15-11-2007, 03:57 PM

No probs.
Shoot me a pm if you need any further help...

**Vios-GT_07** · 15-11-2007, 05:19 PM

i have an indiglo type tacho that used to be plugged into a 4A-GZE.. if you want it's yours

ran off the distributor though, not coil-pack type but i'm very sure it can be plugged and work.. it's 4 inch, two different lights, dimness adjustment, made by APC

**Mitchee** · 16-11-2007, 10:14 AM

I had one of those shiftligt/tacho things in an old car. Its simply 3 wires. Power, earth, tach from coil. I wouldnt recommend it as the readout is a bit delayed, and only updates itself every 1/4 of a second or so, and so the shiftlight is slightly out.

**deviant** · 16-11-2007, 10:59 AM

Cheers for that Mitchee!!

I'm going to have a play with the one Vios has got and see if thats any good.

**Vios-GT_07** · 16-11-2007, 12:22 PM

Autometer's one of the best as it's gas driven ... almost no lag.. but very expensive

with my apc one, i noticed the engine doesn't out-rev the tacho.. even though it's spring driven.. also, if you'll blow the engine because the tacho is that 0.25 seconds slower at telling you when to shift....... er....