Ok here's a couple of pics and I hope a bit of an explanation. Now the wires I'm adding are from the donor car and are related to the plug you need to wire in for the clutch switch. I also used the copper ends on those wires that I actually pulled out of the connectors, its a pain, but I'm trying to make it easy to reverse the install and keep everything clean.
1. Pic dsc00632 and dsc00633..
These are located on the pax side under the kick panel below the EEC. If you look at the black connector, you can see the purple/yellow wire going into the connector. The auto's don't have a wire in that slot in the plug, so go ahead and hook up the purple/yellow there.
You see the two blue plugs there? The car only has one
. The one with several wires going into it is the one you want. The wire your interested in is the red/light blue wire. Now here's the catcher, and maybe the above diagrams will help you, as it seems one of my few brain cells have left me and I can't remember if you need to splice that red/lblue wire onto the existing one or replace the existing one. Another gotcha is, this red/lblue wire actually is spliced onto the grey/yellow wire you will see at the transmission connector and the clutch connector. Anyways....
2. Pic dsc00635 is the connector to feed the wiring harness going to the tranny below the center console at the dash. You can see here that I have wired in the purple/yellow wire from above into there (The purple/yellow wire actually t's off from the wire coming from the EEC side and goes here as well as the clutch wire harness) You will also see where I wired in the grey/yellow wire into the connector. The clutch connector has these wires.
3. Pic dsc00637 deals with the starter interlock relay from the brake pedal. You can wire the clutch switch into both the red/lblue wires on that connector and that will bypass the brake switch.
Hope that helps out a bit. This is for the '90 auto's only as I am sure the other cars are different.
Good luck.