Wiring diagram for 2008 harley Davidson fxstc. I want to install a tach and do not know which of the four wires going into the coil to tap?

Answer 1

The Blue w/orange stripe wire is the front coil wire, where your signal comes from. Any orange w/white stripe wire is good for a power source with the key on. Black to any convenient black wire for your ground. Make sure all of your connections are good and solid, whether taps, pins or splices. Hook up your ground and power first and turn on your ignition switch to insure you have power before bolting everything down tight, do the same next with the signal wire, make your connection then fire up the bike and verify that your getting a good reading. At cold idle you should be around 1000 rpm.

I don't have an fxstc, I own an '06 FLHR with carb, but the Harley wire color codes should be the same.

Your blue/orange wire should be connected at your Ignition Control Module (Pin 6) if you have a carb and run to pin three on the coil connection.

If an EFI bike, pin 29 on the ECM is the coils front, running to pin D at the coil connector. On EFI, there may also be a pink wire coming from pin 3 on the ECM. That is the tach signal if available. Either 3 or 29 from the ECM should provide a signal.