Just put a 93 LT1 with all the wiring from a 93z28 into a 65 olds, and while removing the wiring for the ABS, cruise control, and body module I removed some wires from the ALDL connector that I guess I shouldnt have.
I only removed the wires from the interior side of the large firewall connection at the drivers side bulkhead connection so I should still have the wires there on the engine side wiring of that connection.
I now have only wires at pins A and B, car runs great but I cannot scan the computer. Can anyone tell me which wires are needed and if possible where they come into the car at the bulkhead? I have been searching the net for 1993 wiring diagrams but have not found it yet. I have the 12 pin connector as shown from shbox's site. My SES light does come on with key on and goes out when the engine starts, so I am hoping I am just missing the serial data line to the ALDL connector but I dont know which one I need.
Also since A pin is ground, should the B pin be +12v? Thanks!

 

Found it, Pin M is needed, serial data to the bulkead at the firewall. Not sure why I cut it, must of mistraced a wire.

 

The data wire is a tan wire, from pin D4 of the ECM.

http://shbox.com/1/harness_connector_faces.htm

Shoebox has the harness connector faces for all years. C100 has the tan wire, C230 has the white/black diagnostic request wire from pin D20 of the ECM. The black/white ground wire originates under the dash.

 

Fred,
I checked another 93 harness I have (from a TA, looks the same as camaro) and the tan wire I need (and removed accidentally) comes into the interior of the car at the bulkhead on the drivers side. As you posted it originates from D4 of the ECM. Thanks for the reply, not sure why I cut it but I will replace it tomorrow. If I had not found it I would of ran a new line from C100, it is as you stated a tan wire.
I appreciate your responses to my questions, you have helped me a great deal!