Window switch

Originally Posted by SouthArk370Z

White - Engine RPM input signal. 5-12V pulse. You can use the negative side of one of the coils or the signal from the ECM. See FSM for pinouts.
Red - RPM switch power. Get power from one of the fuse panels and use an on/off switch between the fuse block and the RPM switch. Mount the on/off switch anywhere that is convenient.
Yellow - RPM switch output (NO). Drive a relay with the output and use the relay NO contacts to switch the load (nitrous valve). Run one side of the relay contacts (NO) to the nitrous valve and the other side of the contacts (common) to a fuse and then a power source.
Gray - RPM switch output (NC). Not needed.
Black - RPM switch ground. Run to closest convenient ground.

The micro-switch (NO) is a WOT indicator to enable the relay.