Wav, That is correct. However, the grey wire is already connected (or should be) to the stator signal and routed to the instrument panel. Why would you want to use another wire?
There is not a tach on the motor now, nor is there wire in the harness to connect a tach so It will be a wire as you go type project, thanks for the replies
Wav, What kind of motor is it? Most of the larger HP motors were wired for tachs, although not all used the grey wire color. Some older Mercs used brown for the tach signal. also, the newer motors ran the tach signal through the voltage regulator. The older motors had rectifiers, and you needed to get the tach signal from one of the stator wires.
I just installed my new tach gauge today however I'm not sure what to use as the sending wire. I have a 93 70 HP Johnson (I think). I was told that I can buy the ignition kit to connect to my control panel and it will have ground, 12V ignition, and my tach wire. Is this true? I appreciate any help, and even some help getting my fuel gauge to work as well.
To try and explain it simply, tachometers read off the alternating pulses from the stator. Any of the leads from the stator charging portion can be used for the signal. The designated tach signal wire is merely attached to one of those. Tachs have rotary switches on the back that set it to different numbers of coils in the charging circuit, times two because there is a positive and negative pulse for each coil for each cycle. Tachs measure pulses. That being said, you need a tach that has the setting that you need designated on the rotary switch.
The BRP tach of the right model comes with a harness that you can plug and play. The Teleflex tachometers offer the harness as well.
Or you can easily wire most tachs, that have the correct settings on the rotary dial of course, by either going directly to the ignition switch or by cutting into the main harness.
