ok i need help asap so if you know what your talking about and can help me out thanks

ok im installing a simple 3 wire hook up shift light (power, ground, and tach signal wire) the easy way is for me to splice the wire right before the ecu, i just cant figure out wich wire it is, if you have pics of a b18 ecu, and can circle or point out wich wire it would be it would be so awsome if not then i am screwed and otu of a cigar lighter in my car cuz thats where the light is mounted