Hi.

I bought one external 300 km/h speedometer.
How do I connect it to the speed cable, and witch of the cables are the speed cable?

Best regards

 

speed cable is connectd to the driver side of the transmission. a black thick cord. never hooked an aftermarket speedo so cant help yea there

 

You have an aftermarket mechanical speedometer? Usually they are electronic and I think that would be easier. The Mazda speedometer takes the mechanical cable rotation and creates an electronic pulse. If you car has cruise control this is output on a green wire with red stripe from the gauge cluster. I've tapped into it where it enters the cruise module for my nav system.