what color is the RPM wire going in to the computer on a 97 lude base?

 

I don't know what color the wire is at the ECU but the color of the wire going into the gauge cluster is BLUE, on the 16pin grey connector (it's pin #5 on that connector). That's the engien speed input, it gives a digital PWM signal that changes frequency with RPM change.

Hope that helps! I have the diagrams for that circuit from the HELMS if you want.

 

i believe it's blue too,
i know it is where it hooks up to the coil

 

yeah, i think it's blue also, for the third person. you can hook it up at the coil or the ecu.