Digital tacho wiring?

[TijmenK]

I want to replace my stock gauges with smaller gauges and most of the eBay tachos don't have the mechanical line the speedo has but come with these wires:

How does this work? What are the line lock wires for? And the signal cable can just be spliced into my coil ground?

 

[Sonreir]

Line lock is something that must be lost in translation....

Usually electronic tachs have two power wires and two ground wires. One set is for the back light and the other set is for the electronics running the tach.

The final wire is the sensing wire. Depending on how the tach works, you may have a bit of difficulty. Most electronic tachs for motorcycles will have this wire be wrapped around one of the spark plug wires. When the plug fires, the voltage running through the plug wire will induct into the sensor wire wrapped around it. The electronics can detect the induction and read it as a pulse.

Some models of ignition unit will have a dedicated output specifically for the tachometer.

 

[TijmenK]

Cheers, that makes sense. I'll order one and give it a try, can't go wrong for 10 bucks.