Tacho wiring diagram?

[GreigM]

Does anyone know what colour the rpm signal into the back of the tacho is on an R400? Caterham branded gauges (CAI) with emerald ECU. Want to tap the wire for a signal to datalogger.

[DVandrews]

It should be black and white from pin 12 on the ECU.

Dave

[DCL]

If you've got shift lights, I would use that as it's easier to pick it up on the plug, or lead. Pulse is once per cycle so scale it is x 120 for RPM. [Edit: not sure if that applies to the Emerald ECU]

Edited by DCL on Tuesday 8th July 22:39

[Gingerbread Man]

Is the best place to take a signal for shift lights from just behind the tacho?

[GreigM]

DVandrews said:

It should be black and white from pin 12 on the ECU.

Dave

I do have a black and white which looks like it runs to the back of the ECU, I'll give that a try first....no shift lights installed at the moment. Thanks all.

[GreigM]

Gingerbread Man said:

Is the best place to take a signal for shift lights from just behind the tacho?

I suppose it doesn't matter so long as joining the wire doesn't affect the tacho itself (making the needle go a bit "flaky"). I just chose the tacho as its the obvious place there must be an rpm signal going to.