[jclark003]

I guess I wasn't clear. What I meant was depending on which Floscan instrument you have it may not be connected to the tach sender. If you have the tach option then yes sender is a possibility. If the entire floscan gauge is flickering it may be power related; if it is just the tach reading that is bouncing around it is more than likely the sender.

As far as I know floscan uses the engine tach sender and does not have a separate signal generator. Engine tach sender should be on left side of flywheel housing. It senses the number of teeth on the flywheel.