factory tach....way off?

[fiveoho]

I could not say if it has a dial or not
but
They offer a way of selecting different rpm values

I can say

It ain't got anything to do with the oem tach

It is a separate device apart form the oem tach.

It gets a signal from the ignition ... not the tach
so
You could display both the hosed oem tach values
and
The accurate values from an after market tach or lite

Hows that I didn't even know I knew that much

Grady

i appreciate you explaining.

i got it now

 

[gcomfx.com]

Yeah, sorry about that. You set a tach light built into a tach by the tach like you were talking about. The aftermarket shift lights work independently. So you pick your rpm.... dial, pill, however the manufacturer builds them.... on the light themselves. It will light up when your ignition system hits the rpm you picked on the light.