Simple mini tach question (where does the red and black wire go?)

[surfish95747]

Bought a dime city cycles mini tach and am having a hard time understanding where to plug in the red and black wire. It looks like all the factory speedo and tach wires are bundle together with the factory connector, which ones do I pull out for the tach? I am very new to wires and had done a lot of learning with my manual, etc. thanks! This is for a 1980 cb750k US version.



What I understand is there is a brown/white wire going to the tach lights and a dark green wire, but it looks like these two wires go also to the speedo lights and odometer lights, will this wire need to be spliced into four or something when I install the corresponding speedo (don't have one yet)? I guess the diagram throws me for a loop. Thanks if anybody can help me out.

[TOOLS1]

You are correct in your assumption. The brown/white wire supplies power to all the gauge lights, and the green is the ground.
TOOLS

[surfish95747]

So does the red wire from the tach connect to the brown/white wire from the factory cluster? And the black wire from the tach connect to the green ground? If that is the case than I will need to splice the brown/white and green ground wires into enough connections for both the tach lights and the speedo lights? Thanks for helping me understand.

[TOOLS1]

I do not have any idea which wire is which on the gauge. That is something you will have to look at to figure out. However most of the time the light circuit is not grounded, so it does not matter which is connected to which.
TOOLS

[surfish95747]

Figured it out. The red wire is the power wire and goes to the brown/white wire. Black is ground and goes to green. Thanks.