Got a tach from buddy of mine w/ p/n 107612 on it. There are (+ ) (G)& (S) terminals on it. Can I put this on a 09 RKC and if so can I splice it to the serial data wire or do I have to goto the #3 port on the speedo connector?

 

Tach should work with no problem as long as it is set for the correct pulse code.

+ equals Switched Positive. Tap power from fuse panel, use one that turns off with key.

G equals ground. Find and attach to a good chassy ground.

S equals Sensor. Underneath the left side cover is a bike test port. 3 wires if I remember correctly. One of the three wires is a green with red strip (again if I remember correctly)This is the sensor wire that you will have to tap into for the sensor lead.

You can go to the local hd shop parts counter and tell them that you are thinking about putting a tach on your bike. Pick one from the catalog and ask them to print out the installation instructions for it and it will tell you step by step how and where. They can tie into the harley net and pull up the instruction for anything they sell.