Strange After Market Tach Readings

I have a 2003 non pre 2wd taco that is a manual. It doesn't have an internal tach so i installed a sunpro II tach. The only thing is that I think the tach wire is messed up or I may have hit the wrong wire.

When the car is idling it idles at 500 rpm.
However when I drive the tach peaks at about 1.5 and listening to the engine i shift around 1000. Its an 8000 max tach with a 6000 red line all with equal increments. I looked up written and drawn schematics of the wire and it is described as light green with a black stripe. which is what it is connected to.

And if the wire was the wrong one then the tach wouldnt pick up a reading at all. So it must be something electrical right?

Well im baffled and am looking for some guidance.

 

The tachometer is not configured for your 4-cylinder engine.

I don't know which model SunPro tach you have, but ... Many of them have an adjustment on the back where you set the tach for the number of cylinders you have. The most likely explanation is that yours is set for either 6 or 8 cylinders. This is why it seems to be reading abnormally low.

 

So simple yet I was so blind haha. Thank you soo much, your solution worked perfectly@!