Tachometer question

All Autometer tacos I've had do that. If you find the instruction sheet I'm sure it talks about that. It's NORMAL for an Autometer tach.
Hey Yellow rose,

That doesn't make sense to me. Rod is saying that his Autometer tach is already reading 2000rpm with no signal from the ignition , how would you know what the idle rpm is? Most engines idle at about 800-1000 rpm . Are you saying that the tach reading 2800-3000 rpm at idle is normal or am I not understanding something here?