I have two question, one is I know the blue wire is a rpm signal on the tach, but it's a low signal, I need the high signal rpm wire. wth is it at? somebody let me know. thanks

 

Are you trying to put in an aftermarket tach??? if so, you need to calibrate it to 4 cylinder if its from autometer. Read the instructions on how to calibrate the gauge (they come calbirated for an 8 cylinder motor from the factory).

If you're using the tach wire to put in a remote start alarm, you need to program the alarm to read tach instead of tachless.