ON K5 THRU 1979 MODELS YOU WILL HAVE TO INSTALL THE SHORT ADAPTOR THEN FOLLOW THESE INSTRUCTIONS IN THE PICTURE ABOVE @ SOME ENGINES HAVE TWO HARNESS'S COMING FROM THE ENGINE THE ONE THAT HAS A LIME GREEN WIRE WITH RED STRIPE IS THE ONE WE ARE TALKING ABOUT HERE,,, THE REST OF THE WIRES IN THIS PIGTAIL ARE FOR BIKES THAT TELL YOU WHAT GEAR YOUR IN ALL THE TIME... WE JUST NEED TO SAVE THE GREEN WITH RED STRIPE AND DISCARD THE REST @ ANOTHER VIEW