I'm hoping someone on here can help me. I am installing an aftermarket tach on my wifes 07 sportster 1200. I haven't torn into it yet, but someone told me that since it is not a harley tach I will have to hard wire it. That it won't just plug in as we hoped. Can someone tell me if this is true? And if so, explain how I need to wire it in? Thanks for any help.

 

Most likely. If you install an add on tach made by HD on certain models you will still have to splice into a couple wires. Wires used O/W (power), LGN/V (data link), and the ground wire. The B+ connector plugs into a connector under the seat. The HD tach also uses a digital to analog convertor.

You will have to use the instructions given to you by the manufacturer of your tach. You have not given us anything to go on here ... but most likely you will have to do some re-wiring.