MoTeC Global Forum

My problem is that my dash tacho does not work at all, I have tried another cluster etc but still does not work. If someone knows how to fix this that would be very helpful but I also want to hook up a monster tacho but I don't know where to wire the signal wire to?

I'm running a Motec M4 ECU but I'm not sure what models CDI Module or CDI Coil I have? and of course where I would wire up the monster tacho to..

Your CDI looks like the older single channel CDI unit, p/n 41004. You can find the wiring sheet here http://motec.com.au/filedownload.php/M33-1.pdf?docid=1024.

There are two options for driving the tacho, you can either use the ignition pulse to the CDI on pin 33 of the ECU, or you can configure a dedicated tacho output from the ECU if you have a spare output.
It is better to have a dedicated output for the tacho, especially if you are going to connect a monster tacho.

For the original tacho to work, you should just spice the wire that went to the standard ECU as the 'tacho signal', either to pin 33 on the M4, or another spare output configured as the tacho output. It should just work.
The monster tacho then also splices to this wire, to the 'tacho signal' input. Just make sure the monster tacho you get has an EFI ignition signal input, and not a coil negative input only.

I will have a look at the ECU wiring etc on the weekend..

The monster tacho I have..
http://www.autometer.com/cat_gaugedetai ... 2580&sid=4

If I get the dash tacho working, how would I go about just wiring up a shift lift only?

Thank you for your help.

It looks like that tacho should work, the instructions are a bit vague, but at least it says you can wire it to a 'tacho output on electronic ignition'. That should be a switch to ground type trigger that the M4 has, but it might need a pullup resistor?

If you want to wire a shift light to the ECU, again you can wire it to a spare aux output, light + goes to switched +12v and light - goes to the aux output. Configure the output as 107 - Gear Change Light, and setup the parameters for shift RPM.
An incandescent shift light like some of the autometer one's will probably draw too much current for aux 2, 3 and 4. Their limit is 0.6A. Aux 1 can sink 4A so any light should be fine on it. The LED shift lights are better anyway and don't draw much current.

If you haven't fitted the new tacho yet try the pullup resistor.

I have CA18DET and the tacho wouldn't work on my M880 fitted the resistor now works fine.