i have a 93 astro van 4.3 with the 4l60e tranny and the round plug on the passenger side of it all the wires had been cut at one time before i got it to try to figure out why it wont shift into drive or overdrive and the speedometer wont work... The sensor on the tailshaft is brand new ande even replaced the instrument cluster thinking it could be the gauges but after looking at the round plug on the passenger side the wiring harness has 12 wires on it and the wires coming out of the plug has 13 i got them all color coordinated but i ended up with a extra blue wire and the plug has 2 yellow with blk strip wires but the harness only has 1 black with yellow strip wire... What do i need to do to get this thing working?

 

Try a 4th gen board. We are 3rd Gen F-Body here (1982 - 1992), and NONE of our cars had 4L60E trannies in them - we all had 700R4. The 1994+ F-bodies had the 4L60E trannies.

I do know that the 4L60E is all electronically controlled, including shift points and such - and is all controlled by a seperate computer for the tranny (a PCM). Without those wires attached, I wouldn't drive it at all as serious damage could ensue.