i have a 93 astro with some tranny issues... When it was brought to me to be fixed the speedometer wouldnt work and it wouldnt shift right... So i replaced the speed sensor in the tailshaft put a new cluster in it still nothing... Then we got to looking at the wiring harness on the passenger side of the tranny and all the wires dont match in color... the plug has 1 dark blue, 1 purple, 1 green, 2 yellow with black stripe, 1 blue with white stripe, 1 red with black stripe, 2 pink, 1 white, 1 brown with black stripe,and 1 red... All those match up to the wires going to the tranny but i only have 1 yellow with black stripe and the plug has 2 of those... and i also have a spare black with yellow stripe wire thats 12v with the switch on that runs to the tranny with those wires that i dont know where it goes.. The tranny come out of a 94 chevy caprice which is 13 wire plug but i took the pan off and put the astro 12 wire interneal wiring harness in it..