Aftermarket water temp gauge

[Shanes325]

So I'm looking to get a more detail idea of what temp my engine is at . I have read and searched on how to do the install.but I am still not sure wat sensor wire to tap into. I guess wat I'm looking for is wat color is the signal wire for water temp? Use the oem coolant temp sensor? It's for an 86 m20 ,thanks in advance

[jlevie]

Unless you get a digital gauge that allows creation of a custom calibration curve, you can't use an aftermarket gauge with the OE temperature sensors. You will have to add the sensor for the gauge you pick.