-
You are right that the Nanocom or Hawkeye tools are displaying the real temp being measured by the temp sender unit. It is the computer which is converting this signal into the 4 position "dumb gauge" for the dash.
Your idea to take this signal (or even from a second temp sender) and run a parallel feed direct to the dash temp gauge and disconnect the direct feed from the computer has merit, would just need to work out what size resistor to get the correct range, limit the max volts, and ideally try and match the normal operating point as being around the halfway mark.
-
Hi, unfortunately is not so easy to trick the gauge as it's an analogue gauge and works with PWM signal and the temp senders are simple NTC resistive senders... the ECM calculates the temp based on the voltage drop on the sender's resistance, converts the signal to PWM and manages the gauge within those ranges... actually IMO is not so bad as it seems at first sight cos when the gauge is to leave the middle(betwen 115 and 120*C) the ECM will go in overheat protection and limit fueling too ... if you want to watch the coolant temperatures fit an "engine watchdog" or similar system but IMO it's something which can affect your attention while driving and might give you creeps seeing temperatures above 100*C even if untill 110 is no problem
the best is to have a coolant level warning and IMO as long as the gauge is at the middle and you have enough coolant you can drive it without fear
