Automatic Tranny Questions

[Jeff240sx]

Hey.
I sold a perfectly working '96 auto tranny on Ebay to a semi-local guy. I just got a call saying that the Overdrive doesn't work. I asked about anything funny, and he said while changing the filter, he saw a pair of wires that were disconnected. They are black and white, and he can't see where they get connected to. He also said he'll pay to have them connected, if he KNOWS that those wires are the problem.
So, I have 2 questions.
First, why would all gears work smoothly and fine, yet Overdrive doesn't work?
Second, does anyone know what those wires do, and where they connect? I don't have a FSM, so if someone with a FSM could help, it'd be awesome.
I don't wanna leave this guy high and dry... so if anyone could help me and him... Thanks!
-Jeff

[gsracer]

because on our cars specificly the s14, the overdrive is electric and is engaged by a solenoid, so if it is disconected, it will not work or engage. Thats why when you push the little button on the side of the gear shift it disengages and reengages because it is electric:hammer:

[hotrodman]

White wire supplies current to solenoid and black is ground. In this case one of the wires has a switch to break current flow. On the automatic drive gear select there are probably going to be three wires 12volt supply, acc., and ground. When power is traveling through (light) no flow, no light or blown light. It can be ground controlled or current controlled. This is all electrical assumption. Just my opinion.
Good luck Jeff.;)