M800 Tacho output

[Daniel]

Well if its a 5 volt wave i ned a 12 volt one.

[Daniel]

Just spoke to Motec about this and will try there fix and will let you know how i go.


Daniel

[IJ.]

Bit odd if it needs a 12v signal most dashs are 8v Dan, they drop the voltage needed to run them so a low battery won't affect them as much.

Interested to hear how you go with it!

[MarkMc]

A coil negative tacho is not like an ECU driven tacho so you cannot run them directly from the ECU. A coil negative side give a very large back EMF pulse that drive the tacho, an ECU driven tach works of a much simpler frequency drive from the ECU.

The way around this is to instal an iductive coil of some sort to provide the big back EMF spike you need for a coil negative tacho, we usually use a relay coil.
.
I have attached a basic wiring diagram

[Daniel]

Hi Mark

Thanks very much for the info you have given me.
I had spoken to Peter today about this and said the same thing or
try a 1k resistor from 12volts to the signal wire.

I have just done the 1k resistor and works great.

Will test drive the car this afternoon and see how it goes.

Thanks again for everyones help


Daniel