Raptor Shift Light Install-Honda

Most Hondas have a blue wire that is the engine speed signal.

Examples:
2009 Civic: blue wire on PCM (computer) pin #28. Set shift light to 2 Pulse/rev (4 cylinder mode).  
S2000: Engine speed signal at tach test terminal (blue wire) left rear of engine compartment.

Raptor Shift Light Install-Honda 

Raptor Shift Light Install-Honda