MoTeC Global Forum

My previous M4 install one of the Aux outputs was configured for Tacho and this worked fine, driving the tacho on a BMW E30 M3 1990.

I have recently installed M800 and with the Aux 3 configured as tacho, I have no tacho!

Questions...

1, Is there any difference in the M4 tacho and M800 tacho signals?

2, What type of signal does the M800 output for tacho, i.e wave length, polarity ect?

3, Is there anything specific I need to do to drive such a tacho?

Thanks

Steve

Just add 1 Kohm pullup between Tacho Signal and 12v. 4.7K ohm will most likely work too

Thanks. That had been suggested by a friend. I have a 1kOhm resister ready for tomorrow. Failing that a 4.7k will be found.

Cheers

Steve

If the 1K doesn't work the 4.7k definitely won't, higher the resistor the lower the current.

If it is a coil negative tacho then it will need an inductive load from a realy coil. If the 1k resistor does not work PM me and I'll post a diagram.

1k resister fitted today and it works fine.

Thanks for the input

Steve