Tacho fix for Aftermarket ECU

[angus337]

Just wanted to check what the best option is for fixing the Rev counter once coil packs are fitted and the Dizzy and Coil are removed. I’ve tried a tach fix module but can’t get it to work. http://www.ms2tuning.com/products.html

Following the removal of the Dizzy and coil I have three wires which I assumed are as follws:

Blue and White - live from ECU
Blue and White - Feed to Tacho
Black - Ground

Wired up the Tach fix module to these three wires and the Tacho feed from the Megasquirt ECU but get no response on the rev counter.

[carsy]

What wire have you broken into for the tacho feed. Are you sure you have the right one as it should work. I seem to recall the wire i broke into at the back of the tacho was white and slate. The unit i have also needed its own feed so had 4 wires.

12v switched supply
input from ecu
ground
feed from unit to tacho.

Edited by carsy on Monday 17th June 17:27

[phazed]

If in doubt, speak to Shaun, MS2 Tuning, he has the correct little gizmo and will tell you how to wire it;

07891512664

[Sardonicus]

angus337 said:

Just wanted to check what the best option is for fixing the Rev counter once coil packs are fitted and the Dizzy and Coil are removed. I’ve tried a tach fix module but can’t get it to work. http://www.ms2tuning.com/products.html

Following the removal of the Dizzy and coil I have three wires which I assumed are as follws:

Blue and White - live from ECU
Blue and White - Feed to Tacho
Black - Ground

Wired up the Tach fix module to these three wires and the Tacho feed from the Megasquirt ECU but get no response on the rev counter.

Should be 4 wires not 3 1. switched 12v + 2. Ground - 3. Ign pulse in 4. Ign Tacho Out.

Edited by Sardonicus on Monday 17th June 20:59

[angus337]

The Tachfix module is one from Shaun so I think the probelm lies in finding the corret wires to wire it up, rather than a problem with the tachfix itself.

Had another check last night and can only find the three wires listed above. The picture below is the only diagram That I could find on the Web, shaded Area is The stuff I've removed. Looks like I'm missing the White Switched live. Any one know how this is routed in the engine bay.



Alternative option is to install the module under the dash or in the foot well. will have look tonight to see how easy this is likely to be.

[phazed]

Mine is in the footwell wired into a new loom by Shaun.

Just ask him, do you want his mobile number?

[carsy]

Nick YHM.

[Sardonicus]

Under the dash right next to the Tacho is where mine is based you can find everything you need as far as earths supplies etc in that location you can wire the box of tricks directly to the Tacho this way without tracing wires

[Tavan]

This is for a 99 Griff using the plug and play solution with loom made up by Shaun. May be different on yours.

I put the tach module behind the dash. New loom has a wire to go to the tacho. Find the white 26 (or so) way connector block behind dash and locate the white with blue trace wire on the dash side of it that goes to the tacho. On the engine/ECU side of the block connector there will be either a white with blue trace wire or a white with black trace wire that connects to the -ve terminal of the coil via a series resistor. Snip that wire and join the loom tacho wire to it.

Looking at it from the coil -ve terminal end: the cable from the coil terminal splits into two. Each leg has an in-line resistor. One leg goes to tacho via the 26 way connector (that's the one you want to connect to). The other leg goes to the ECU.

HTH

[Mr Supercharged]

The connector referred to above is a 24 way sumitomo connector. it looks like this:



If you are looking for a switched 12v supply and are struggling to find one in your dash area you will find one on the brown 7 way sumitomo connector which is right next to the one illustrated above.